prelude prelude /ˈpreɪˌluːd/

noun

1. () Something that serves as a preceding event or introduces what follows  ( preliminary , overture , prelude )
   something that serves as a preceding event or introduces what follows
    Training is a necessary preliminary to employment
   training is a necessary preliminary to employment
    Drinks were the overture to dinner
   drinks were the overture to dinner
   
2. Music that precedes a fugue or introduces an act in an opera  ( prelude )
   music that precedes a fugue or introduces an act in an opera
   

verb

1. (music) play as a prelude  ( prelude )
   (music) play as a prelude
   
2. Serve as a prelude or opening to  ( prelude )
   serve as a prelude or opening to