Theme music is a musical composition which is often written specifically for radio programming, television shows, video games, or films and is usually played during the title sequence, opening credits, closing credits, and in some instances at some point during the program. The purpose of a theme song is often similar to that of a leitmotif.
The phrase theme song or signature tune may also be used to refer to a signature song that has become especially associated with a particular performer or dignitary, often used as they make an entrance.