Prelude, Piece of Music That Opens a Performance

This page is the CodyCross answer for the clue below from Concert Hall, Group 593, Puzzle 3 (Decrescendo).

Question is: Prelude, Piece of Music That Opens a Performance

and the answer is: OVERTURE

Word Meaning:

OVERTURE — (obsolete) An opening; a recess or chamber.

Definitions from Wiktionary.