A music supervisor is a person who combines music and visual media. According to the Guild of Music Supervisors, a music supervisor is “a qualified professional who oversees all music related aspects of film, television, advertising, video games and other existing or emerging visual media platforms as required.” In the musical theatre industry, a music supervisor is often responsible for managing a team of music directors working on any number of musical productions. In visual productions, the music supervisor usually works with the directors, writers or producers to choose which songs are best suited for the scenes.

A music supervisor is somebody with a broad and encyclopedic music expertise and a sophisticated knowledge of music licensing and negotiation. Typically, a music supervisor proposes previously recorded songs to the director or producer of a film, advertisement, television show, trailer, promo, video game, or any other form of visual media. A music supervisor will usually act as a liaison between the creative and business ends of the process. Once a song is approved, they approach the rights holders of that song to seek permission to license (usually creating master recording licenses and synchronization licenses) and to work out the financial details of the song's use. In many instances, the artist or songwriter of the recorded song is given the opportunity to accept or decline the synchronization of their song. This position is most active within media-based industries, including live events, television, film, advertising, theatre, and video gaming. Music supervisors may work within production companies, film studios, networks, music supervision companies, or do freelance work.

A supervisor's responsibilities are to locate, secure and oversee music-related talent. They liaise between the rights holders of the recorded music involved and the director of the project they have been hired to work on. In addition, they advise, generate and work within financial parameters of the project they are hired to work on. They must deliver musical elements within a timely manner and secure legal rights of the song before it is used. The music supervisor will gather the appropriate information to list credits and, in certain cases, will manage royalty collection.

The overarching responsibility of a music supervisor is to meet the needs of a project's director and producer. This means catering to the creative goals of a project under a strict budget: often less than 5% of a project's total budget.

The director/producer will discuss their vision for the project with the music supervisor, and how they expect the music to enhance this vision. The visual media will then be spotted by the supervisor – a process of choosing where selected music will be inserted. Traditional spots include the main title, opening credits, and closing credits, while additional spots are incorporated to trigger emotional responses from viewers. Scores, or background music, are also an important consideration for enhancing visual media. Scores can range from the background to a dramatic scene to television bumpers – the music signifying leading into or coming back from a commercial break.

After being given or creating a budget, the supervisor must select appropriate music for the project – either by licensing existing songs/scores, or creating new songs/scores. In the selection process, a music supervisor may choose to seek the help of a third party licensing company or a music publisher, which will pitch songs to the supervisor from within their library of music. If creating new music, the supervisor may become responsible for additional roles, including securing artists or composers, facilitating the production and recording process, overseeing finances, and finalizing post-theatrical uses of the soundtrack. When using pre-existing music, the supervisor's duties focus on the legal and financial aspects of licensing and negotiating. A large percentage of a music supervisor's job revolves around music clearance alone.

When it comes to royalty collections, a music supervisor will sometimes be in charge of arranging this source of the selected artist's revenue. Royalties for music placements are paid out by Performance Rights Organizations (such as ASCAP, BMI, and SESAC in the United States). In order to detect the placements an artist has made with visual media, these companies need to be aware of their placement. Depending on the type of project (ad placement, television show, etc.). the music supervisor will have to either make sure the artist is credited properly, send video clips of the placement to the publisher (which will then be sent to the proper Performance Rights Organization),or create a cue sheet of all of the songs used in the project

Many directors and producers will choose to work with a single supervisor for a project, however it varies from project to project. For example, music supervisors can be hired at an entertainment company as an “in house” staff member to manage the supervision for several projects (such as at an advertising agency). A production company may also hire a supervisor on a project-by-project basis (such as hiring one supervisor for an entire television series as seen with Gossip Girl or The O.C.). Music supervisors may also be hired on a show-by-show basis (ex. AMC's Mad Men, which has used multiple music supervisors).