prelude

An introductory performance, event, or action preceding a more important one; a preliminary or preface.

A piece or movement that serves as an introduction to another section or composition and establishes the key, such as one that precedes a fugue, opens a suite, or precedes a church service.

A similar but independent composition for the piano.

The overture to an oratorio, opera, or act of an opera.

A short composition of the 1400s and early 1500s written in a free style, usually for keyboard.

To serve as a prelude to.

To introduce with or as if with a prelude.

To serve as a prelude or introduction.

To preface; prepare the way for; introduce as by a prelude; foreshadow.