prelude (n.)

"introductory performance; a preliminary to an action event or work," 1560s, from French prélude "notes sung or played to test the voice or instrument" (1530s), from Medieval Latin preludium "prelude, preliminary," from Latin praeludere "to play beforehand for practice, preface," from prae- "before" (see pre-) + ludere "to play" (see ludicrous). Purely musical sense of "movement or piece forming the introduction to a musical work" is attested in English by 1650s. Related: Preludial; prelusive; prelusory; preludious; prelusion.