soundtrack

Plural: soundtracks

Noun

• sound recording on a narrow strip of a motion picture film
• A narrow strip running down a movie film that carries the recorded sound in synchronization with the pictures.
• The sound (especially the music) component of a movie, video game, etc.
• A recording of such music for sale.
• A background sound that is part of a larger event.

Verb

• To provide, or to act as the sound or music component of a film.