For any person interested in composing for movies or television, it is very important to understand the difference between different kinds of background scores. This article will precisely do that.

The music that we hear while watching T.V. shows or movies is not as simple as it seems. Other than the complicated compositions there is also very specific classification of the music.


When classifying, there are two primary questions:


  1. Is it original music by the composer?


  1. Is it Diegetic or Non-Diegetic?


Diegetic: Sounds or music that can be heard by the characters in the film/show.


Non-Diegetic: Sounds or music that can only be heard by the audience not the characters in the film/show.



Based on the answers we get, the classification becomes easy. You may think why is it so important? The thing is, respectful payment to the composers for their work depends upon these categories. These categories also help to keep a track of royalties.



Here are the four categories of film/television music:





Underscore is background music. It supports emotion, drama or mood of the scene.

It is generally instrumental but can sometimes be vocal as well. This music is only heard by the audience, not by the characters in the movie, hence it is non-diegetic. Furthermore, it can be composed in any style as considered appropriate for the need of the movie/show.



Song Score


As the name suggests, the use of a song to underscore a scene in order to support drama/mood/emotion is song score.

The song is usually prerecorded by some other artist hence it is not the film composer’s original music. Since only the audience can hear the song, it comes under the category of non-diegetic music.



Source Music


Music that appears to come from a source inside the scene like radio, jukebox, musician etc. is known as source music.

It is diegetic because characters as well as the audience can hear it. It helps to establish time period and location. This music is usually prerecorded music, which requires license.

If the composer writes it then it comes under the category of source score. In any other case it needs a license/permission from its original composer.



Source Score


This is a hybrid of source music and underscore. The composer writes this music you can also hear it from a source visible on the screen. This makes it diegetic because the audience as well as the characters can hear it. It generally has a deeper meaning, dramatic purpose or thematic connection to the movies plot.

Bollywood movies where the characters are dancing to the various songs is a very good example of source score.