Other forms: soundtracks
The music that a movie is set to is its soundtrack. Some soundtracks are composed and recorded especially for a film, while others are made up of many songs by different musicians.
TV shows and video games often have soundtracks too, although the concept started with films. During the silent film era, musicians would sometimes play live music to accompany a movie screening. The origin of the term soundtrack goes back to approximately the same time that the first "talkie," or film with sound (1929's "The Jazz Singer"), was screened for audiences. A recorded album featuring the music from a movie is also called a soundtrack.