Prelude

noun
1.
a preliminary to an action, event, condition, or work of broader scope and higher importance.
2.
any action, event, comment, etc. that precedes something else.
3.
Music.

a relatively short, independent instrumental composition, free in form and resembling an improvisation.
a piece that precedes a more important movement.
the overture to an opera.
an independent piece, of moderate length, sometimes used as an introduction to a fugue.
music opening a church service; an introductory voluntary.

verb (used with object), preluded, preluding.
4.
to serve as a prelude or introduction to.
5.
to introduce by a prelude.
6.
to play as a prelude.
verb (used without object), preluded, preluding.
7.
to serve as a prelude.
8.
to give a prelude.
9.
to play a prelude.
noun
1.

a piece of music that precedes a fugue, or forms the first movement of a suite, or an introduction to an act in an opera, etc
(esp for piano) a self-contained piece of music

2.
something serving as an introduction or preceding event, occurrence, etc
verb
3.
to serve as a prelude to (something)
4.
(transitive) to introduce by a prelude