The music supervisor typically handles the negotiation and licensing of outside music used for a film, and handles other music business matters such as negotiating record contracts for the soundtrack album, negotiating publishing deals for the film's music, and generally working with all the parties involved in creating or supplying music for a film and television project.
The music supervisor is a key player in selecting outside music ("licensed music" or "source music") which includes songs and music used in on-camera situations such as music playing in a restaurant, bar, or club.
More and more, however, music supervisors are becoming extensively involved in the process of hiring and supervising the score composer hired for the film or television project. For this reason, it can be important for both score composers and songwriters (not to mention record companies and publishers) to be known by music supervisors.
Successul relationships with music supervisors can lead to many oppotunities in the business.