Online Encyclopedia
Search over 40,000 articles from the original, classic Encyclopedia Britannica, 11th Edition.
ORGAN
Online EncyclopediaEncyclopedia Home :: ORC-PAI
del.icio.us it!
|
ORGAN , in See also:music, the name (from Gr. epyavov, See also:Lat. organum, See also:instrument) given to the well-known See also:wind-instrument. The notes . of the organ are produced by pipes, which are blown by See also:air under pressure, technically called wind.
Pipes differ from one another in two See also:principal ways—(r) in See also:pitch, (2) in quality of See also:tone. (1) Consider first a See also:series of pipes producing notes of similar quality, but differing in pitch. Such a series is called a stop. Each stop of the organ is in effect a musical instrument in itself. (2) The pipes of different stops differ, musically speaking, in their quality of tone, as well as sometimes in their pitch. Physically, they differ in shape and See also:general arrangement. The See also:sounding of the pipes is determined by the use of keys, some of which are played by the hands, some by the feet. A See also:complete stop possesses a See also:pipe for every See also: Every stop is provided with mechanism by means of which the wind can be cut off from its pipes, so that they cannot sound even when the keys are pressed. This mechanism is made to terminate in a handle, which is commonly spoken of as the stop. When the handle is pushed in, the stop does not sound; when the handle is pulled out, the stop sounds if the keys are pressed. An organ may contain from one to four manuals or keyboards and one set of pedals. There are exceptional See also:instruments having five manuals, and also some having two sets of pedals. The usual See also:compass of the manuals approximates to five octaves, from C to c"" inclusive. The compass of the pedal is two and a See also:half octaves, from C to f'. This represents the pitch in which the notes of the pedal are written; but the pedal generally possesses stops sounding one See also:octave See also:lower than the written See also:note, and in some cases stops sounding two octaves below the written note. Each See also:manual or pedal has as a See also:rule one soundboard, on which all its pipes are placed. Underneath the soundboard is the windchest, by which the wind is conveyed from the See also:bellows, through the soundboard to the pipes. The windchest contains the mechanism of valves by which the keys See also:control the See also:admission of wind to the soundboard. The soundboard contains the grooves which receive the wind from the valves, and the slides by which the handles of the stops control the transmission of the wind through the soundboard to the pipes of the different stops. The grooves of the soundboard are spaces See also:left between wooden bars glued on to the table of the soundboard. There is usually one groove for every key. The grooves of the See also:bass notes, which have to See also:supply wind for large pipes, are broader than those of the See also:treble. The bass bars are also thicker than those of the treble, that they may the better support the See also:great See also:weight which rests on the bass portion of the soundboard. The table forms the See also:top of the grooves. The grooves are generally closed below with the open grooves seen from above. i See also:leather, except the opening left in each, which is closed by the key-See also:valve or pallet. The sliders are connected with the draw-stops or stop-handles, which are covered in with stout upper boards, on which the pipes stand. The stop-handles are pulled out, and holes are then bored straight down through the upper boards, sliders and table to admit the wind from the grooves to the pipes. When the sliders are shifted by pushing in the handles, the holes no longer correspond, and the pipes are silenced. Pipes are divided first into flue-pipes and See also:reed-pipes. Flue-pipes are blown by a wind See also:mouthpiece characteristic of the organ, while in reed-pipes the wind acts on a See also:metal See also:tongue vibrating on a reed, and the See also:motion of the tongue determines the speech of the pipe. Pipes are made either of See also:wood or of metal. Wood flue-pipes are generally of the See also:form of a rectangular parallelepiped, metal flue-pipes of a cylindrical shape. Reed-pipes are conical or pyramidal, and widen towards the top. Some flue-pipes are made with stopped ends; these as a rule sound a note about an octave lower than the corresponding open pipes of the same length. Such are the stopped See also:diapason, See also:bourdon, and stopped See also:flute. The general elementary theory of the resonance of a pipe is tolerably See also:simple. The effective length of the pipe is determined by measuring from the upper See also:lip to the open end in open pipes, and from the upper lip to the stopper and back again in stopped pipes. To this is added an See also:allowance for the effect of each opening, since the See also:condition of perfect freedom from constraint does not subsist at the opening itself. The corrected length is traversed twice (backwards and forwards) by sound, in the See also:time of one vibration of the result See also:ant note. This describes in a rough and general manner the way in which any disturbance gives rise to the note of the pipe; but the theory of the mouth-pieces is a much more difficult See also:matter, into which we cannot here enter. conical the resonance of the But the resonance of the See also:body of the pipe is generally the same as the note produced. The tongue of a reed-pipe alternately opens and closes the See also:aperture of the reed. In this way it admits, pulses of wind to the body of the pipe; these, if they recur at the proper intervals, maintain its vibration, which takes See also:place when the note produced corresponds to the resonance of the pipe. The reed itself has its vibrating length determined by a See also:wire which presses against it. The See also:free end of this wire is touched with the tuning See also:tool until a satisfactory note is produced. The pitch of the different stops is commonly denoted by the conventional approximate length of the pipe sounded by C, the lowest key of the manual. Even in incomplete stops which have no bass, the length of the pipe which C would have if the stop were extended down serves to indicate the pitch. The conventional length of the C-pipe for stops having the normal pitch of the keys is 8 ft.; a pipe having twice this length sounds the octave below, a pipe having half that length the octave above, and so on. Thus stops which sound the octave below the normal pitch of the keys are spoken of as 16-See also:foot stops. Even where the pipes are stopped so that the actual length is only 8 ft., they are spoken of as having " 16-ft. tone." Similarly 32-ft. stops sound two octaves below the normal pitch of the keys. But if these notes are produced by stopped pipes, whose actual length is only 16 ft., they are spoken of as having " 32-f t. tone." Sixteen-foot and 32-ft. stops are specially characteristic of the pedal, where the names also signify the length of the open pipe which would sound the note actually produced by the lowest C. Of stops higher than the normal pitch of the keys, the octave is denoted by 4 ft. if made with open pipes, 4-ft. tone if stopped; the twelfth is commonly spoken of as 21, the fifteenth or See also:double octave as 2 ft. Higher-sounding stops are occasionally used, but these generally form See also:part of " mixtures," and the foot-lengths of the See also:separate ranks are not usually given. The true or accurate lengths of the pipes vary within considerable limits. The See also:base of the scales (dimensions) varies according to the See also:standard of pitch, and the voicing and the complicated natural See also:laws of pipes produce other deviations from simple relations, so that the conventional dimensions can only be regarded as a simple means of classifying the stops according to their pitch-relations. For this purpose they are essential; they are continually appealed to in discussion and description; and they are almost invariably marked on the stop-handles in all countries, so that a moderate knowledge of See also:foreign nomenclatures, combined with the See also:habit of seizing the meaning of the figures such as 16, 8, 4, on the stop-handles, will frequently suffice as a key to the complexities of a foreign organ. Each of the manuals, or rows of keys, of an organ constitutes a separate organ, which is more or less complete in itself. The names of the different manuals or See also:organs are great organ, swell organ, See also:choir organ and See also:solo organ. The fifth manual, where it occurs, is the See also:echo organ. The above is the usual See also:order in point of development and frequency of occurrence, although the solo is sometimes preferred to the choir organ. The great organ is in a certain sense the principal See also:department of the organ. It maybe regarded as formed by a completely See also:developed series of those fundamental stops which constitute the solid basis of the tone of the instrument. If an instrument be constructed with only a single manual this necessarily assumes, in general, the characteristics of a great organ. The great organ is called " grande orgue " in See also:French, and first manual or " See also:haupt-werk " in See also:German. It is proposed to describe the principal organ-stops under the II Groove See also:uRI Pc C dn x the table, windchest and pallet. 1116 See also:MEW iiam- angles to fig. 2. l of f •1 I. J. r. In reed-pipes which are simply body is nearly the same as that of an open pipe of the same length. Where the form is irregular no simple rule can be given. XX. 9 what greater detail. heads of the manuals to which they belong. The enumeration will not be exhaustive, but will include all the usual types. The great organ begins generally with stops of 16 ft. in large instruments. In some cases a 32-foot sounding stop is introduced, See also:meat but this cannot be said to be a proper characteristic of the great organ. The See also:foundation tone is of 8 ft.; the stops ORGAN O1g8n. of higher pitch serve to add brilliancy; those of i6 ft., which sound the octave below the normal pitch, se~ve to add gravity and weight to the tone. Sixteen-foot stops are commonly spoken of as " doubles," their conventional length being twice that of stops of normal pitch. The i6-ft. stops are the i6 double open diapason, and the 16 bourdon or double stopped diapason, to which, in very large instruments, there may be added a 16 double See also:trumpet. The double open diapason on the great organ consists usually of metal pipes, having moderate " See also:scale," or transverse dimensions. These are of the same general See also:character as the pipes of the See also:ordinary open diapason, though they are made somewhat less powerful. In the better instruments of the second class as to See also:size this stop alone would probably be regarded as representing suitably and sufficiently the class of doubles on the great organ. .It gives great body to the general tone, and appears decidedly preferable to the bourdon, which frequently takes its place. The 16 bourdon, when used on the great organ, is made of rather small scale and See also:light tone. It gives great body to a large great organ and affords interesting combinations with other stops, such as the 4-ft. flute. It is used either alone in smaller organs of the second class, or in addition to a double open in larger instruments. The i6 double trumpet is a trumpet (large reed stop) sounding the octave below the normal pitch. It is used generally in instruments of the largest size, but is somewhat more See also:common in See also:Germany. It is useful in giving a massive character to the tone of the full great organ, which is See also:apt to become disagreeable on See also:account of the great development of stops of a piercing character. If, however, the double trumpet is rough in tone, it is apt to communicate to the whole a corresponding impression. We now proceed to the 8-ft. stops (the reeds come at the end according to ordinary usage). An ordinary great organ may contain Great 8 stopped diapason, 8 open diapason (one or more), 8 Great gamba and 8 hohlflote. The 8 stopped diapason on the o organ great organ is usually of moderate scale, and some See also:con- feet. siderable fulness of tone. Few stops admit of more variety and individuality in their quality of tone than the stopped diapason; but too frequently the great organ stopped diapason fails to attract See also:attention on its merits, being regarded simply as an in-considerable portion of the foundation tone. If there is any one stop which in itself represents the organ as a whole it is the open diapason. The pipes of this stop are the typical metal pipes which have always been characteristic of the See also:appearance of the organ. A single open diapason stop is capable of being used as an organ of sufficient See also:power for many purposes, though of course without variety. The pipes of this stop are called " principal " in German, this appellation apparently corresponding to the fact that they are the true and See also:original organ-pipes. The See also:English appellation of " diapason " has been taken to mean that these are the normal pipes which run through the whole compass. This, however, does not appear to be the actual derivation of the See also:term; originally it is technically applied to the organ-builder's rule, which gives the dimensions of pipes; and it appears that the application to the stop followed on this meaning.
The scales, character and voicing of the open diapason vary with See also:fashion, and are different in different countries. We may distinguish three principal types. The old English diapasons of the days before the introduction of pedal organs into See also:England were characterized by a See also:rich sweet tone, and were not very powerful. They were generally voiced on a light wind, having a pressure See also:equivalent to that of a See also:column of See also:water of from 2 to 21 in. The scale was in some cases very large, as in See also:Green's two open diapasons in the old organ at St See also:George's, See also:Windsor; in these the wind was light, and the tone very soft. In other cases the scale was smaller and the voicing bolder, as in See also:Father See also: The German diapason was of an entirely different character from the English. The heavy bass of the pedals has been an essential characteristic of the German organ for at least two or three centuries, or, as it is said, for four. The development of the piercing stops of high pitch was equally general. Thus foundation See also:work of comparatively great power was required to maintain the See also:balance of. tone; the ordinary German diapason was very loud, and we mayalmost say coarse, in its tone when compared with the old English diapason. The German stop was voiced as a rule on from 31 to 4 in. of wind, not quite twice the pressure used in England. The French diapason is a See also:modern variety. It may be described as presenting rather the characteristics of a loud gamba than of a diapason. In other words the tone tends towards a certain quality which may be described as " nasal " or metallic, or as approaching to that of a See also:string instrument of rather coarse character. Some modern English builders appear to aim at the same See also:model, and not without success. The tone of a diapason must be strong enough to assert itself It is the foundation of the whole organ tone. It is the voicer's business to satisfy this condition in See also:conjunction with the requirement that the tone shall be full and of agreeable quality. The 8 spitzflote may be regarded as a variety of open diapason. The pipes See also:taper slightly towards the top, and the quality is slightly stringy. This stop was much used at one time in place of a second open diapason. But it appears better that, where two open diapasons are desirable, they should both be of full diapason quality, though possibly of different strengths and dimensions. The ad-mixture of stringy qualities of tone with the diapasons is always to be deprecated. The 8 gamba was originally an See also:imitation of the See also:viola da gamba, a sort of See also:violoncello. When made of a light quality of tone it is a pleasing stop; but its use in the great organ instead of a second open diapason is greatly to be deprecated for the reasons just stated. The 8 hohlflote is an open flute, usually of wood, and of small scale. If made to a moderate scale and fully voiced it possesses a full pleasant tone, which is a useful support to the foundation tone of the great organ. The 8 clarabella differs from the hohlflote in being usually of rather large scale, and having the open pipes only in the treble. In old organs a separate bass was generally provided; now it is more usual to supply the stop with a stopped bass. The 4-ft. stops of the great organ comprise the 4 principal and the 4 flute. The 4 principal is the octave of the open diapason, generally of somewhat reduced scale and light but See also:bright quality of Great tone. The use of the word " principal " in connexion organ with this stop is purely English, and is said to be con- 4 feet. nected with the use made of it as the standard of tuning for the whole organ. The Germans and French both designate this stop as " octave." Of the 4 flute there are several varieties—open, stopped, wood, metal and See also:harmonic. The harmonic flute has open metal pipes of double the conventional length, which speak their octave. This is determined partly by the voicing, partly by making a small hole about the See also:middle of the length, which determines the motion as that of the two separate lengths between which the hole lies. Harmonic flutes have a sweet but full and powerful tone. Other flutes are generally rather light, except the waldflote, which is a powerful stop of a somewhat hooting quality. The great organ flute is frequently used to give brilliancy to light combinations. Thus it may be used with the stopped diapason alone, or with the 16 bourdon alone, or with any of these and either or both of the open diapasons. The ordinary use of the 4-ft. stops is to add a degree of loudness to the diapasons. This is accompanied with a certain measure of keenness, which may become disagreeable if the 4-ft. tone is disproportionately strong. The ordinary practice is to use the 4-ft. tone very freely. The 2; twelfth stop sounds See also:fiddle g on the C key. It is composed of diapason pipes, rather small and gently voiced. Its Great use is said to be to thicken the tone, which it certainly orgaa does. But how far the particular effect produced is stops of desirable is another question. It is generally necessary high pitch that this stop should be accompanied by the fifteenth or other octave sounding stop of higher pitch. The 2 fifteenth, or superoctave, of the great organ consists of diapason pipes sounding notes two octaves above the normal pitch of the keys. The 2 See also:piccolo is a fluty stop of less power, having the same pitch. The 2-ft. tone is commonly used as giving a degree of loudness to the great organ beyond that obtainable with the 4-ft. tone. The modern great organ fifteenth is generally a very powerful stop, and requires great caution in its use in organs of moderate size, or in limited spaces. The old English high pitched stops had little power, and their brilliancy was capable of pleasing without offence. The modern great organ up to fifteenth can only be heard with comfort in very large spaces. Under such suitable circumstances the fifteenth is capable of giving to the whole tone a ringing or silvery character, which lends itself specially to contrast with the tone of reeds. This See also:peculiar keen tone requires for its full development the mixtures. Mixture, sesquialtera, See also:furniture, cymbal, See also:scharf, See also:cornet, are various names applied to a description of stop which possesses several ranks or several pipes to each note. The pipes of each note sound a chord which is generally composed of concordant notes of the harmonic series whose fundamental is the proper note of the key. Modern mixtures generally consist of fifths and octaves. Their See also:composition is not the same throughout the whole range of the See also:keyboard. A three-See also:rank mixture may consist of the following (the See also:numbers signify intervals, reckoned along the scale) C—c (See also:tenor) 15—19—22 4 to top 8—I2—15. For a somewhat larger full mixture this may be modified as follows C—c' (middle) 15—19—22 c'# to top I— 8—12—15. A See also:sharp mixture suitable for a large instrument may be as follows Five Ranks. C —C' 15—19—22—26—29 c'#—f''# 8—I2—15—19—22 g"—c'° I— 8—12—15—19 to top I— 5— 8—12—15. The last two compositions are given by See also:Hopkins in his great See also:treatise on the organ. The See also:early mixtures generally included the tierce (17th, or two octaves and a third). The German practice was to unite this with a twelfth, carrying the See also:combination 12-17 throughout the keyboard under the name of sesquialtera. The combination is not now usually provided. The old English sesquialtera was ordinarily simply a form of mixture, as was the furniture. The mounted cornet consisted usually of five ranks 1—8—12—15—17. It extended from middle c upwards. The pipes were raised on a small soundboard of their own. The stop was used for giving out a See also:melody. It is now obsolete. The question of the employment and composition of mixtures is of the greatest importance with respect to the See also:good effect of the full organ proper, i.e. without reeds. With reference to the whole question of keen-toned stops it may be laid down that their free employment in the great organ does not produce a good effect unless the organ is situated in a very large space. If this' is the See also:case, properly proportioned mixtures are capable of giving to the tone of the full diapason work a character which is brilliant without being over-powering. The contrast between this class of tone and that afforded by the reeds is one of the most charming and legitimate effects within the range a_ the instrument. We now pass to the reeds. The 16-ft. trumpet has been already alluded to, and there remain 8 trumpet and 4 clarion or octave Great trumpet. These are both stops of great power. The best organ trumpets possess also richness and smoothness of tone. reeds. Stops of this class can be used with the diapasons only, producing what may be described as a rich-toned blare of moderate strength. The more usual employment of the reeds is in connexion with the entire great organ, the whole forming the ordinary fortissimo of the instrument. The second department of the English organ is the swell organ. The whole of the swell pipes are enclosed in a See also:box, faced on one or Swell more sides with a set of balanced shutters. When these. organ. are closed the tone is almost completely muffled. When the shutters are opened, by means of a pedal usually, the sound bursts out. In order that the use of the swell may be effective, it is necessary that the shutters should See also:close tightly, and that there should be a sufficient See also:volume of tone to produce an effect when they are opened. The swell is of entirely English origin; it has been introduced in Germany to a very small extent, but more widely in See also:France. It is usually called " recitatif " on the See also:Continent. The chief characteristic of the swell is the rich and powerful volume of reed-tone of a peculiar character which it contains. But other stops are also of importance. We consider them in order. The 16 bourdon, small scale, is very commonly used in swells. It assists in giving body to the tone. It occupies, however, a large space within the swell box; and where the choice between it and a 16-ft. reed has to be made there can be no doubt that the reed should be preferred, as it contributes so much more to the development of the characteristic swell tone. The 16 contra fagotto is the usual name of this stop. It imparts great richness to the tone of the other swell reeds. The 8-ft. diapason work is principally valuable for the soft effects obtained from it. The diapasons are voiced less loudly than for the great organ; and with the shutters closed they sound very soft. The dulciana is the softest stop generally available; and either this or some similar stop is introduced into the swell for the purpose of obtaining effects of the most extreme softness. Space within the swell box has generally to be economized. The complete bass of the open diapason or dulciana requires an 8-ft. swell box, whereas even a 16-ft. reed can be See also:bent See also:round so as to go within a smaller box if necessary. The open diapason and the dulciana are therefore often cut See also:short at tenor c, and completed, if desired, with stopped pipes. The 4 principal and the 4 flute stops are similar to the corresponding stops in the great organ, but are somewhat lighter in tone. The 2 fifteenth and mixtures are much more pleasing in the swell than in the great organ. The shutters tone them down, so that they cannot easily become offensive. Added to the reeds, they give a peculiar brilliancy to the full swell. But perhaps their most pleasing use is when all the diapason work of the swell is used alone, and as a contrast to the reeds. The usual reeds are as follows, besides the doubles already mentioned: 8 See also:oboe, 8 cornopean, 8 trumpet and 4 clarion (octave trumpet). The oboe (hautboy) is a conventional imitation of the orchestral instrument. It is a stop of delicate tone, and perhaps is at its best in solo passages, softly accompanied on another manual. The cornopean has a powerful See also:horn-like tone. It is the stop which, more than any other, gives to the English swell its peculiar character. The trumpet is used in addition to the cornopean in large instruments. The clarion serves to add brightness and point to the whole. The vox humana is also frequently placed on the swell. The third department is the choir organ. The 8-ft. Ch oir work may contain 8 stopped diapason, 8 open diapason, organ 8 gamba, 8 keraulophon and 8 hohlflote. As a rule no open diapason is provided for choir organs, unless they are larger than usual; but a small open is most useful as a means of obtaining a better balance than usual against the other manuals. The stopped diapason is generally made to contrast in some way with that on the great organ. The hohlflote, or its representative, is generally a lighter stop than what would be put on the great organ. The gamba is better placed in the choir organ than in the great or the swell. Such stops as the gamba and the keraulophon are frequently placed in the swell with the See also:idea of adding to the reediness of the tone. But this is fallacious. Their tone is not strong enough to assert itself through the shutters, and their peculiar character is therefore lost. On the choir organ, on the other See also:hand, the sort of strength required is just about what they possess, and they show to See also:advantage. The keraulophon is a stop invented by See also: In organs which have no solo manual there is usually a clarionet (See also:cremona, See also:cromorne or krummhorn, in old organs sometimes corno di bassetto) on the choir, and often an orchestral oboe (real imitation of the instrument). These are reed-stops. The dulciana and another soft stop, the salicional, salcional or salicet (of similar strength, but slightly more pungent quality), are often placed on the choir. They are, however, hardly strong enough to be of much use there, and in the swell they are useful for effects of extreme softness. In very large instruments a fifteenth and a mixture are sometimes placed on the choir, which in this case has a complete series of diapason work. If the fifteenth and the mixtures are light enough the result is a sort of imitation of the tone of the old English organ. It also forms a useful echo to the great organ, i.e. a passage played on the great may be repeated on the similar but fainter tone of the choir with the effect of an echo. In instruments of the largest size the choir is sometimes provided with a very small bourdon of 16-ft. tone, which See also:helps to give to the tone the character of that of a small full organ without reeds.
The solo organ is comparatively modern, at all events in its See also:present usual form. A See also:fourth manual was not unknown in old
German organs; but the contents of all four resembled solo.
each other in a general sort of way, and there was nothing organ like the English swell or the modern solo. The solo
appears to have arisen with Cavaille-See also:Coll in France, and See also: Thus the French term for the solo is " clavier See also:des bombardes "; and in the earlier English solos the " See also:tuba mirabilis " was usually prominent. A solo organ may suitably contain any of the following stops: 8 tromba (a powerful reed on heavy wind), 8 harmonic flute (powerful tone and heavy wind), 8 clarionet and 8 orchestral oboe (real imitations of the instruments) and 8 vox humana (conventional imitation of the human See also:voice). The last three stops are reeds. They may be with advantage enclosed in a swell box, having a separate pedal. In very large instruments a . complete series of both diapason and reed stops is occasionally placed on the solo. But there does not seem to be much advantage in this arrangement. We now come to the pedal. This forms the general bass to the whole organ. See also:Thirty-two foot stops only occur in the largest instruments; they are as follows: 32 open diapason pedal. (wood or metal), 32-ft. tone bourdon and 32 contra organ See also:trombone, posaune, bombarde, See also:sackbut (reed). The 32-ft. open diapason, whether wood or metal, is usually made of large scale, and produces true musical notes throughout. Its musical effect in the lower part of its range is, however, questionable, so far as this depends on the possibility of recognizing the pitch of the notes. It adds great richness to the general effect, particularly in large spaces. The 32-ft. tone bourdon is not usually a successful stop. It rarely produces its true note in the lower part of its range. The 32-ft. reed on the pedal has See also:long been a characteristic of the largest instruments. With the old type of reed it was rarely pleasant to hear. The manufacture has been greatly improved, and these large reeds are now made to produce a fairly smooth effect. Deep reed notes, when rich and good, undoubtedly form one of the principal elements in giving the impression of power produced by large organs. From this point of view they are of great importance. Nevertheless the effect of large pedal reeds is generally more satisfactory to the performer than to the listener. The t6-ft. pitch may be regarded as the normal pitch of the pedal; the principal stops are as follows : 16 open diapason (wood or metal), 16-ft. tone bourdon, 16 violone (imitation of double bass) and 16 trombone or posaune (reed). The 16-ft. open diapason on the pedal assumes different forms according to circumstances. As a rule the character is sufficiently indicated by the stop being of wood or metal. The wooden open is generally of very large scale, and produces a ponderous tone of great power and fulness, which is only suitable for the See also:accompaniment of the full organ, or of very powerful manual combinations. Such a stop is, as a rule, unsuitable in organs of moderate size, unless supplemented by lighter 16s for ordinary purposes. The metal open is of considerably smaller scale (in fact all metal pipes are effectively of much smaller scale than wooden pipes of similar See also:diameter). The metal gives a clear tone, lighter than that of large wooden pipes, and pleasanter for ordinary purposes. The metal open combines advantageously with a bourdon. In the largest organs both wood and metal open 16s may be suitably provided. Where metal pipes are made a feature in the organ-case, both the double open diapason in the great organ and the metal 16 of the pedal may be properly made of good metal (polished See also:tin or spotted metal), and worked in to the design of the organ-case' The same applies to the 32-f t. metal opens of the largest instruments. This saves space in the interior, and gives the large pipes See also:room to speak, which is apt to be wanting when they are placed inside. The 16-f t. tone bourdon on the pedal may be made of any scale according to circumstances. If it is the chief bass of the organ it is made very large and with great volume of tone. Such stops are unsuitable for soft purposes, and a soft 16, usually a violone, is required in addition. If the loud department of the 16 tone is otherwise provided for the bourdon may be made of moderate strength. It may also be made very soft, like a manual bourdon. These three different strengths ought always to be provided for in an instrument of a complete character. The violone is also made of all three strengths. In a few cases it furnishes the principal bass; frequently it furnishes the moderate See also:element; and it is often applied to obtain a very soft 16-ft. tone. The t6-ft. reed is very common. The observations made as to the effect of 32-ft. reeds are applicable also in this case. The 8-ft. department of the pedal is only less important than the 16, because it is possible to replace it to a certain extent by coupling or attaching the manuals to the pedals. The usual 8-ft. pedal-stops are as follows: 8 principal bass (metal or wood), 8 bass flute (stopped), 8 violoncello (imitation of the instrument) and 8 trumpet. The remarks made above as to the scale of open 16s apply with little See also:change to the pedal principal. Only, since the manuals are generally coupled, it is perhaps best to provide the large scale wood-stop, which presents the powerful class of tone in which the manual diapasons are deficient. The bass flute is almost a necessity in combination with the light t6-ft. tone. A composition ought to be provided by which the pedal can be reduced to these two elements by a single See also:movement. The violoncello is sometimes used instead of the bass flute for the last-named purpose, for which, however, it is not so suitable. It is a favourite stop for some solo purposes, but is not of much general utility. The 8-ft. trumpet serves to give clearness and-point to the tone of the 16-ft. reed. In the short See also:preface to Mendelssohn's Organ Sonatas it is stated that everywhere, even in pianissimo, it is intended that the t6-ft. tone of the pedal should be accompanied by 8-ft. tone. For the purpose of realizing this as a general direction the soft t6-ft. and 8-ft. stops are required; large instruments are, however, occasionally found which possess nothing of the See also:kind. The following stops of higher pitch are occasionally found on the pedal: 53 twelfth bass, 4 fifteenth bass, mixture and 4 clarion. These serve to make the pedal tone practically See also:independent of coupling to the manual, which is a matter of great importance, especially in the performance of certain compositions of See also:Bach and other writers, who appear to have been independent of couplers. In some instruments two sets of pedals are provided, which may be described as great and choir pedals. The great pedal is in the Second usual position; the choir pedal is in front of the other, and sloping. It is so placed that the feet See also:rest on it naturally pedal' when stretched out in front of the performer. There is a choir pedal of this kind in the organ in the See also:minster at See also:Ulm, built by Walcker of See also:Ludwigsburg. It is a very large instrument, having too Anything down to one-third tin and two-thirds See also:lead is called tin. But " pure tin " should have over 90% of tin. Absolutely pure tin could not be worked. Spotted metal is said to have from one-third to two-thirds tin. Under one-third tin no spots are said to rise, and the mixture has the general characters of lead.sounding stops. It has no compositions, which indeed are but little known in Germany ; and without some arrangement such as this a soft pedal would hardly be obtainable. There are a few other instruments which have choir pedals, but they have not been introduced into England. In organs which have a single manual the characteristics of the great and choir organs are usually See also:united. In organs which have two manuals the lower usually represents the united great and choir, the upper is the swell. In organs which have Anangethree manuals the lower is usually the choir, but some- meat of times combines choir and solo, the middle is the great, manuals. and the top is the swell. In organs which have four manuals the order is solo, swell, great, choir, the solo being at the top and the choir at the bottom. Compositions are See also:mechanical contrivances for moving the stop-handles in See also:groups at a time. The ordinary form consists of pedals, which project from the front just above the pedal keys. Composl-The arrangements are various. We may refer to the arrangement in the organ at Windsor, given later on. Cons. A See also:species of composition was introduced by See also:Willis some years ago, and has been adopted in many large English instruments, which acts by means of a series of See also:brass disks placed just under the front of the keys of each manual, within reach of the thumb. These See also:act by means of pneumatic levers. A slight pressure on one of the disks sets the See also:machine attached to it in See also:action, and the required change in the stops is made without any exertion on the part of the performer. The connexion between the keys and their pallets is made by various mechanisms, some of which are very See also:ancient. In square and trackerwork (fig. 7) General the old squares were made of wood. Thev meth". resemble in See also:function the squares used for taking See also:bell-wires round a corner. The trackers are slight strips of wood, having screwed wires whippbd on to their ends,which hold by leather buttons. The trackers See also:play the part of the bell-wires. Where pressure has to be transmitted instead of a pull, thin but broad slips of wood are used, having pins See also:stuck into their ends to keep them in their places. These are stickers (fig. 8). Back-falls (fig. 9) are narrow wooden levers turning on pins which pass through their centres. The See also:fan See also:frame (fig. to) is a set of backfalls having one set of ends close together, usually corresponding to the keys; the other ends are spread widely apart. The See also:roller See also:board (fig. II) is a more general mode of shifting the movements sideways. The roller is a slip of wood, or a See also:bit of metal See also:tube, which turns on two pins inserted into its ends. It has two arms projecting at right angles to its length. One of these receives the pull at one point, the other gives it off at another. In case a pull has to be transmitted to more than one See also:quarter, 1 a roller will sometimes r–r ~~ have more than two arms. The name of couplers (fig. 12) is given to the mechanical stop by which the keys of one manual are made to take down those of another, or those of the pedal to take down those of the manuals. Some old forms of the mechanism could not be put on while any of the keys were depressed; others had a tendency to throw the fingers off the keys. These forms have been entirely superseded. That now used consists of a series of backfalls centred on a movable support. The one set of ends is connected with the moving keys; the other set of ends is pierced by the wires of the trackers or stickers from the keys to be moved. In the one position of the support these ends play freely over the wires; in the other they are brought up against the buttons of the trackers or against the stickers to be moved. The usual couplers are —each of the manuals to the pedal, swell to great, swell to great octave, swell to great sub-octave, swell to choir, choir to great sub-octave, and solo to great. The swell octave and sub-octave couplers are sometimes placed on the swell itself. The objection to this is, that if they are used when the swell is coupled tr. 1 the great organ, as is very commonly the case, the octaves are reached through two couplers. And, as couplers are not generally screwed up quite tight, the octaves are often not sufficiently put down to sound in tune. The choir to great sub-octave coupler was used chiefly as a substitute for a double on the great organ. It is common in organs of the transition See also:period, but is not a good arrangement. The pneumatic See also:lever (fig. 13) consists of a small power bellows attached to each key, so that the depression of the key admits high-pressure wind to the power bellows. The power bellows then performs the work of opening the valves, &c. In large organs the work to be done would be beyond the reach of the most powerful See also:finger with-out this See also:device. Similar devices are sometimes applied to the compositions and other mechanical arrangements. Pneumatic transmission, with many other mechanical devices, was invented by Willis. It consists of a divided pneumatic action. The pneumatic wind, instead of being at once admitted to the power bellows, is made to See also:traverse a length of tubing, at the farther end of which it reaches the work to be done. This principle admits of application to divided organs, the pneumatic transmission passing under the See also:floor, as in the organ at St Paul's Cathedral. Ventils are valves which control the wind-supply of the different groups of stops. They were much recommended at one time as a substitute for compositions. The See also:practical difference is that com- positions shift the stop-handles, so that one can always see what there is on the organ; ventils leave the stop handles unmoved, so that the Other inconveniences might be mentioned, but it is enough to say that practical See also:opinion appears decidedly to condemn the use of ventils. The original pedal boards of Germany were See also:flat and of very large scale. The early practice in England was to make them very small, Arrange- as well as of short compass. Of See also:late the compass Cf', menu thirty notes, has been universally adopted with scalesmiddle of the pedals to the great organ keys, it is agreed, should be 32 in. But as to the forward position there is a difference. The resolutions said that " a plumb-See also:line dropped from the front of the great organ sharp keys falls 2 in. nearer the player than the front of the centre short key of the pedal board." The old arrangement gave usually 11 in. for this distance. But it is thought that the change has not gone far enough, and 4 in. has been found preferable. There is scarcely any single arrangement which is so important for the comfort of the player as having sufficient space in this direction (fig. 14). The second matter is the See also:provision of some other means of acting on the swell than by the swell pedal. The use of the swell pedal is inconsistent with the proper use of both feet on the pedal keys; and there is no doubt that incorrect habits in this respect are commonly the result of the English use of the swell pedal. In fact, players sometimes keep one foot on the swell pedal all the time, so that proper pedal playing is impossible. Arrangements have been devised by means of which a movable back to the seat can be made the means of acting on the swell. The first " recommendation " of the See also:College of Organists illustrated the requirement;. it was, that " the See also:consideration of organ-builders be directed to the widely-expressed See also:desire for some means of operating on the swell in addition to the ordinary swell pedal." G. See also: As an example of an organ of a complete but not enormously large character, we give the details of the organ at St George's See also:Chapel, Windsor, which was rebuilt by Messrs Gray and See also:Davidson, according to See also:Sir See also:Walter Parratt's designs, in the See also:year 1883. Choir Organ (2i-in. wind). Dulciana 8 Keraulophon 8 Stopped diapason 8 See also:Viol d'orchestre . 8 FIute 4 Piccolo . . Corno di bassetto (reed) . 8 Solo Organ (6-in. wind). Harmonic flute 8 Orchestral oboe 8 Tromba . . . 8 Pedal Organ (4-in, wind). Open diapason (wood) . . 16 Violone (metal) . . . . 16 Bourdon (wood) . . . . 16 Wood flute .. . . 8 Trombone (wood tubes) . . 16 Couplers. Solo to great. Swell to pedal. Swell to great. Great to pedal. Solo to pedal. Choir to pedal. Pneumatic action to great organ and its couplers. The arrangement of the stops and compositions is as follows:—Left. Over the keys. Right. Solo. Couplers. Swell. Choir. Tremulant. Great. Pedal. (Knob below swell keys.) 1 These are the old mixtures. about varying from 2; to 21 in. from centre to centre of the the per. naturals; 2g in. is the scale now recommended. A large former. number of organs have been provided with See also:concave radiating pedal boards. The objections to this arrange- ment are mainly two: They present different scales at different distances from the front; and, except just in front, they become so narrow that the smallest foot can hardly put down the pedals singly. This renders difficult the old Bach See also:style of playing, the essence of which consists in putting the feet over each other freely, so as to use the alternate method as much as possible; and this requires that the back of the pedal board shall be as available as the front. The diversities of the arrangements of different organs present a great difficulty. The best players take a certain time to See also:master the arrangements of a See also:strange instrument. With a view to the intro- duction of uniformity a See also:conference on the subject was arranged by the See also:Col- lege of Organists in London, and a series of resolutions and a series of recommendations were published which deserve attention (1881), though they have now been withdrawn. We may mention that the parallel concave form was recommended for the pedal board, and 28 in. for the scale. The positions of the stops of the various organs were to be as follows: Left. Right. Swell. Solo. Pedal. Great. Couplers. Choir. The order of compositions, &c., from piano to forte was to be in all cases from left to right. The groups of compositions were to be in the order from left to right—pedal, swell, couplers, great. Two other points of detail may be alluded to. One is the position of the pedal board with reference to the keys. The height_from the Mt- great Orgizn ssz `rte See also:Olaf arrars9onterd 2 ,College o{Ory itn :sts IMotgdoden College & iS'''GeongeS Windsor 4 i Four manuals, C to al", 58 notes. Pedal, C to f, 30 notes. Great Organ (32-in. wind). Double open diapason . . 16 Large open diapason . . 8 Open diapason . 8 Stopped diapason . 8 Clarabella .. .. 8 Principal . .. 4 Harmonic flute . . Twelfth .. .. 21 Fifteenth .. .. 2 Sesquialteral . . 111 ranks Harmonic piccolo 2 Posaune 8 Clarion 4 Swell Organ (3-in. wind). Lieblich bourdon 16 Open diapason 8 Stopped diapason 8 Dulciana 8 Vox coelestis' 8 Principal ... Octave duiciana Fifteenth .. Mixture2 . Contra fagotto 16 Cornopean 8 Oboe 8 Vox humana 8 Clarion 4 4 4 2 . III ranks Great to pedal in and out Reduce pedal to violone Great to pedal in. One swell pedal controls two sides of the swell box. The other controls the box in which the orchestral oboe is placed. The vox humana is in a box which is always shut, inside the swell box. See also:History of the Modern Organ. The history of the ancient organ is dealt with in a separate See also:section below. The first keyboard is said to have been introduced into the organ in the cathedral at See also:Magdeburg about the close of the 11th See also:century. There were sixteen keys; and a See also:drawing exists in a work of the 17th century' which purports to represent them. They are said to have been an ell long and 3 in. broad. The drawing represents a complete octave with naturals and short keys (semitones), arranged in the same relative positions as in the modern keyboard. In early organs with keyboards the keys are said to have required blows of the fist to put them down. In these cases probably sounding the notes of the See also:plain See also:song was all that could be accomplished.
As to the precise time and conditions under which the key-board assumed its present form we know nothing. It is commonly said that the change to narrow keys took place in the course of the 14th century, and the semitones were introduced about the same time.
Many examples of organ keyboards still exist, both in England and on the Continent, which have See also:black naturals and See also: Harpsichords with black keyboards also exist. The mode of blowing practised about the time of the introduction of the first keyboard appears to have been that which Bellows, ultimately developed into the method still generally used in Germany. There were a great many separate bellows, each like a magnified See also:kitchen-bellows, but provided with a valve, so that the wind could not return into the bellows. One See also:man had See also:charge of two of these. Each foot was attached to one bellows, and the blower held on by a See also:bar above. It was possible, by raising each of the two bellows in turn and then resting his weight upon it, to produce a See also:constant supply of wind with the pressure due to his weight. A great many such bellows were provided, and it seems that each pair required one man; so that great numbers of blowers were employed. A slight modification is enough to change this method into the German one. Instead of fastening the feet to the bellows and pulling them up, the blower treads on a lever which raises the bellows. The bellows being loaded then supplies the wind of itself. The bellows thus used have See also:diagonal hinges, and various expedients are employed to make them furnish steady wind. But the English See also:system of See also:horizontal reservoirs and feeders appears far See also:superior. The invention of the pedal may be set down to the 15th century. About that time the organ assumed on the Continent of See also:Europe Pedal. the general form which it has retained till lately, more especially in Germany. This may be described generally as having a compass of about four octaves in the manuals and of two octaves in the pedal, with occasionally extra notes at the top in both, and frequently " short octaves " at the bottom. German short octaves are as follows. The manual and pedal appear to terminate on E instead of C. Then the E key sounds C, F =F, F# = D, G = G, G# = E, and the rest as usual. There were often three, sometimes four, manuals in large organs. 1 See also:Praetorius, Theatrum Instrumentorum. The character of all these was in general much the same, but they were more softly voiced in See also:succession, the softest manual being sometimes spoken of as an echo organ. There are one or two examples of the echo as a fourth or fifth manual in England at the present time, in organs which have been designed more or less under German See also:inspiration. The old echo was long ago superseded by the swell in England. A few ancient cases survive in a more or less altered condition. Of these the following are worthy of mention, as bearing on the question of date. Cases. See also:Sion (See also:Switzerland). See also:Gothic. A sma.. instrument . 1390 See also:Amiens. Originally Gothic. Large, with 16-ft. pipes . . 1429 See also:Perpignan. Gothic. Large, with 32-ft. pipes . . . . 1490 See also:Lubeck. One of the finest Gothic organs in Europe. 32S. 1504 (or, according to Hopkins, 1518). In all these the cases are sufficiently preserved to make it almost certain that pipes of the same lengths were originally employed. The actual pipes are generally modern. Shortly after this date we find See also:Renaissance cases. At La Ferte See also:Bernard (dep. See also:Sarthe) part of the substructure is Gothic, and is known to be of date 1501; the organ above is Renaissance, and is known to be of date 1536. At St See also:Maurice, See also:Angers, an organ was built in 1511, with Renaissance case, two towers of 32-ft. pipes, 48 stops and a separate pedal. An account of the instrument in a proces verbal of 1533 furnishes good See also:evidence. In the 16th century, therefore, the organ had attained great completeness, and the independent pedal was general on the Continent. We cannot follow the history of German organs through the intervening centuries; but we propose to give the items of one of the principal organs of the Silbermanns, the great builders of the 18th century—namely, that See also:standing in the Royal See also:Catholic Church, See also:Dresden. Without being an enormously large instrument it is complete in its way, and gives a very good idea of the German organ The account is taken from Hopkins. The date is 1754,2 Great. Principal Bourdon . Principal Viola da Gamba Rohrflote . . Octave . Spitzflote Quinta . . Quintaton Principal Gedackt Unda See also:Maris Octave . . Rohrflote Nassat . . Choir. 8 tone Quinta . . 1 4 Siffiote . 1 4 tone Mixtur . 111 ranks 2 a Sesquialtera u 2 Chalumeaux . 8 tone Pedal. Mixtur . 1v ranks Pausan(trombone) 16 Trompette . . 8 Clarin . . . . 4 Accessories. Tremulant echo. Tremulant great. Compass. Manuals—C to d"' in alt. Pedal—C1 to tenor c. The chief difference between English organs and those of the Continent was that until the 19th century the pedal was absolutely unknown in England. The heavy bass given by the pedal being absent, a lighter style of voicing was adopted, and the manuals were usually continued down below the 8-ft. C so as to obtain additional bass by 2 The writer heard this instrument as a boy, and has a very pleasant recollection of the general effect. @well.. D 'w p Composition Pedals. Great and pedal combined German organ. 16 Octave 2 • 16 tone Tertia . . ^ . I! 8 Mixtur . . iv ranks 8 Cymbel . 111; 8 tone Cornet v 4 Fagott 16 4 Trumpet 8 4 Clarin . Echo. 16 tone Octave 2 8 Tertia I R 8 tone See also:Flageolet . 1 8 tone Mixtur 1v ranks 4 Echo . . . v 4 tone Vox humana . 8 tone 4 Gedackt Principal Rohrflote Nassat Octave . Untersatz Principal . Octave-bass Octave . . 32 tore 16 . 8 • 4 Echo to great. Great to pedal. English organ& playing octaves with the hands. Thus the old organ (date 1697) o Father Smith in St Paul's Cathedral had manuals descending to the 16-ft. C (C1), with two open diapasons throughout. Green's old organ at St George's,'Windsor, had manuals descending to the 12-ft. F, also two open diapasons throughout, no F. But the more usual practice was to make the manual descend to the See also:lot G, leaving out the G#. At the Revolution most of the organs in England had been destroyed. Shortly afterwards Bernard Smith, a German, commonly called Father Smith, and See also: See also:Burney writes (1771): " It is very extraordinary that the swell, which has been introduced into the English organ more than fifty years, and which is so capable of expression and of pleasing effects that it may be well said to be the greatest and most important improvement that was ever made in any keyed instrument, should be utterly unknown in See also:Italy; and, now I am on this subject, I must observe that most of the organs I have met with on the Continent seem to be inferior to ours by Father Smith, Byfield or Snetzler, in everything but size ! As the churches there are very often immense, so are the organs; the tone is indeed somewhat softened and refined by space and distance; but, when heard near, it is intolerably coarse and noisy; and, though the number of stops in these large instruments is very great, they afford but little variety, being for the most part duplicates in unisons and octaves to each other, such as the great and small 12ths, flutes and I5ths; hence in our organs, not only the See also:touch and tone, but the imitative stops, are greatly superior to those of any other organs I have met with." (As to these opinions, compare what is said on great organ open diapasons above.) In the course of the 18th century most of the old echoes were altered into swells, and the swell came into almost universal use in England. The development of the swell is inseparably associated with the peculiar quality of English swell reeds. These must have originated during the development of the swell. We hear of a " good reed voicer " named See also:Hancock, who worked with Cranz, changing echoes into swells. However it originated, the English reed is beautiful when properly made. The original swells were usually short in compass downwards, frequently extending only to fiddle g. It is only lately that the value of the bass of the swell has been properly appreciated. Short-compass swells may be said to have now disappeared. The organ in St See also:Stephen's, Coleman See also:Street, was probably nearly Avery's in its original condition at the date when it was old described by Hopkins. It was built by Avery in 1775. English At all events the following arrangements might very organ. well have been the original ones. The pedal clavier without pipes is no doubt a subsequent addition, and is omitted. Great. Sesquialtera—III ranks. Mixture—u ranks. Trumpet. Clarion. Cornet to middle c—v ranks. Choir. Stopped diapason. Principal. Flute. Swell. Cornet—III ranks. Trumpet. Hautboy. Compass. Great and choir—G1 to e", Swell—fiddle g to a"'. no G,#. This gives an excellent idea of the old English organ. There are several different accounts of the introduction of pedalsinto England. It took place certainly before the end of the 18th century, but only in a few instances; and for long after the usual arrangement was simply to provide a pedal clavier, usually from F1 or G, to tenor See also:cord, which took down the notes of the great organ. Unison diapason pipes (12-ft.) were occasionally used. In one or two cases, as in the transition states of the old organ at St George's, Windsor, a 24-ft. open diapason was employed as well as the unison stop. But a more usual arrangement, of a most objectionable character, was to combine the G1—c pedal-hoard with a single octave of so-called pedal-pipes, extending from the 16-ft. to the 8-ft. C; so that, instead of a See also:uniform progression in ascending the scale, there was always a break or repetition in passing C. About the middle of the 19th century it began to be generally admitted that the German arrangement of the pedal was the better, and the practice gradually became general of providing a complete pedal-board of 2-1 octaves (C f'), with at least one stop of 16-ft. tone throughout, even on the smallest organs that pretended to be of any real use. The study of the classical See also:works of Bach and Mendelssohn went hand in hand with this change; for that study was impossible without the change, and yet the desire for the study was one of the principal motives for it. In the meantime See also:Bishop, an English builder, had invented composition pedals, which so greatly facilitate dealing with groups of stops. About the same time (185o) the See also:mechanics of the organ were advanced by the general introduction of the pneumatic lever into large instruments; the whole mechanism of the organ was revolutionized by Willis's improvements; and the organ-builders of England, having obtained from the Continent the fundamental ideas necessary for completeness, advanced to a point at which they appear to have been decidedly ahead. In the early part of the last quarter of the 19th century, the future of the English organ appeared to be one of great promise. Much confidence was See also:felt in the brilliant combinations of Willis's mechanism. The employment sent See also:day of See also:electricity had reached a certain See also:stage, and the organs. necessary fundamental mechanism, under the name of the electro-pneumatic lever, was to be obtained in a practical form. Several new devices were in the air, by means of which the control of the various valves was accomplished by the action of wind, traversing channels, with complete abolition of trackers, and even of stop slides; and Willis's classical mechanisms, including those for acting on stop slides pneumatically without See also:direct mechanical connexion between slide and handle, were almost universally adopted in large organs. The delicate device of pneumatic lever on pneumatic lever, by which alone the small electromagnetic impulses available could be made to do heavy work, had obtained recognition. If there was an occasional failure, it was thought to be no more than might be expected with work of a novel and delicate character. And it was confidently expected that these devices would, in time, with the improvements associated with practical use, come to be reliable. This expectation has not been realized. The objections to the modern pneumatic, and still more to the electropneumatic machinery, are of two kinds—See also:noise and inefficiency. Noise in the Key Action.—We take as the standard of comparison the old tracker organ, without See also:pneumatics. There was always a certain amount of noise. Now, even in the best instruments of Willis himself during his lifetime, and still more in the best instruments of the present day, the noise of the key action is judged to be as See also:bad as in the old tracker organ. The pneumatics have to be driven by a powerful wind; the consequence is they get See also:home with a knock. Noise in the Stop Action.—If in a large instrument with pneumatic drawstop action one of the compositions which affects several stops is put in action, the movement of the stops is followed by a See also:blow like a See also:hammer, which is caused by the pneumatics getting home under the powerful force employed. This is much worse than any-thing there was in the old organ. Inefficiency in the Key Action; Delay and Cyphering.—This chiefly shows itself in delay, both at the depressing and at the recovery of the key. Some of the causes are the size of the pneumatic bellows, which takes time to fill and time to empty; and, very often, defective regulation of the valves. The regulation of the valves is an See also:art Open diapason. Stopped diapason. Principal. Twelfth. Fifteenth. Fifteenth. Cremona to tenor c. Open diapason. Stopped diapason. Principal. Pedals la England. 26+ in itself, and it is often the case that the performance in this respect can be greatly improved by going over the regulation. The test is the possibility of executing shakes and repetitions. It is quite common to find mechanism by the first organ-builders of the day on which shakes or repetitions cannot be executed. Pneumatic transmission is also specially liable to cause delay. In divided organs the swell is usually on the far See also:side from the keys, and the pneumatic transmission tubes pass it under the floor. The swell touch is then considerably worse than the great. In all cases there must be some delay on account of the time the See also:pulse takes to traverse the transmission tube with the velocity of sound. And if a pneumatic bellows has to be filled at the far end the delay will be more. Some of the delay experienced in large buildings may be due to the time taken in supplying the See also:energy necessary for setting up and maintaining the vibrations of the air in the building. This should, however, have been the same with the old tracker action; and the opinion of old players is unanimous that they never experienced anything of the kind. The shake and repetition are the only real tests so far as the action is concerned. Inefficiency in the key action also takes the form of " cyphering," i.e. a note sticks down. With the old tracker organ this could generally be cured without much difficulty by working on the action, and with the separate pneumatic lever something could be done. But the modern types of elaborated action are entirely enclosed in wind-See also:chest and sound-board. It was always foreseen that these types would be dangerous, unless they could be made quite perfect, and they have not been made perfect. When a note sticks, there is no way of curing it except to get at the inside of the wind-chest, or to remove all the pipes belonging to the note. A case happened recently where, during a performance on an organ by a first-See also:rate modern builder, two cypherings took place. To cure the first all the pipes belonging to the note were removed. In the second the last three pages of a Bach See also:fugue were played with a note cyphering all the time; and such cases are of frequent occurrence. Inefficiency in the Stop Action.—In this case the power provided is insufficient to move the stop slide. As there is no direct connexion between slide and handle, nothing can be done but to get inside the organ and move the slide by hand. A case has recently occurred where an organ by a first-rate builder, in constant use, and perfectly cared for, got one of the slides stuck while in use. The organ was locked, so nothing could be done. The same happened to another slide a couple of days later. It is also an everyday experience that the pneumatic compositions are insufficient to move the stops; sometimes they move the stops about halfway, when a sort of wail is heard. One practical result is—where an organ is not too large to be dealt with by the old mechanical methods, there is much to be said for adhering to them. It seems See also:worth while to mention two suggestions by which these imperfections in large organs might be reduced to a minimum. For blowing, See also:motors for stop action, &c., the writer would suggest the employment of the See also:Armstrong See also:hydraulic See also:accumulator system, at a pressure of say boo lb on the square See also:inch. The pumping of the system would be done by See also:external power (electricity, See also:gas, oil or See also:steam), quite away from the building containing the organ. The blowing would be done by the hydraulic system at a point near the organ. The small hydraulic motors attached to the stop slides, swell, &c., might have almost See also:infinite power and be perfectly noiseless. The key-work should be pneumatic and should use Willis's floating lever. The swell pedal should be hydraulic, with the floating lever, as also the action of the back of the seat if employed for opening the swell. The effect of the floating lever is that the movement of the work corresponds exactly with the movement of the part connected with key or pedal. The connexion with the key would have a regulation so that the lever would begin to move a little later than the key, the regulation being adjusted by trial so as to give shakes and repetitions. The principle of the floating lever is the same as that of the steam steering See also:gear in See also:ships. The control of the power is attached to the floating centre. It is always such that the movement of the work brings back the floating centre into its standard position, and it acts like a fixed centre with added power. As to the general arrangement of the instrument, it is desired to make two protests. Firstly, the organ chamber is a monstrosity. Shutting up the organ in a confined space is simply throwing See also:money away. An organ of a quarter the size would do the work better if not shut up in an organ chamber. Secondly, it has become customary to separate the different parts of an organ, putting the pipes of the pedal, great and swell perhaps in different places at a distance from one another, and the soft choir organ, which should be close to the singers, perhaps, as in one actual case, in a remote position where it cannot be heard at all and is useless for accompaniment. The parts of an organ so dispersed will not give a tone which blends into a whole. The practice is undesirable. The divided organ with pneumatic or electric transmission is to be avoided for all reasons. Additional information and CommentsThere are no comments yet for this article.
» Add information or comments to this article.
Please link directly to this article:
Highlight the code below, right click, and select "copy." Then paste it into your website, email, or other HTML. Site content, images, and layout Copyright © 2006 - Net Industries, worldwide. |
|
|
[back] ORFORD, ROBERT WALPOLE, 1ST EARL OF (1676-1745) |
[next] ORGANISTRUM |