prelude

An introductory or preliminary performance or event.

musicA short, free-form piece of music, originally one serving as an introduction to a longer and more complex piece; later, starting with the Romantic period, generally a stand-alone piece.

programmingA standard module or library of subroutines and functions to be imported, generally by default, into a program.

figurativeA forerunner to anything.

Something that serves as a preceding event or introduces what follows

“training is a necessary preliminary to employment”

“drinks were the overture to dinner”

Music that precedes a fugue or introduces an act in an opera

To introduce something, as a prelude.

To play an introduction or prelude; to give a prefatory performance.

Serve as a prelude or opening to