Background music
Although background music was by the end of the 20th century generally identified with Muzak
Muzak Holdings LLC is a company based in metro Fort Mill, South Carolina, United States, just outside of Charlotte, North Carolina. Founded in 1934, Muzak Holdings is best known for distribution of background music to retail stores and other companies....

 or elevator music
Elevator music
Elevator music refers to instrumental arrangements of popular music designed for playing in shopping malls, grocery stores, department stores, telephone systems , cruise ships, airports, doctors' and dentists' offices, and elevators...

, there are several stages in the development of this concept.
In the Baroque
Baroque music
Baroque music describes a style of Western Classical music approximately extending from 1600 to 1760. This era follows the Renaissance and was followed in turn by the Classical era...

 and Classical music era music could be performed as a background to other activities. For instance:
  • French kings of the baroque era could have music performed during their stately dinners.
  • Opera or other public music performances could have such a high "social function" character that few people would actually listen to the music being performed.

Incidental music
Incidental music
Incidental music is music in a play, television program, radio program, video game, film or some other form not primarily musical. The term is less frequently applied to film music, with such music being referred to instead as the "film score" or "soundtrack"....

 is music in a play, radio/tv program or some other form that is not primarily musical, adding atmosphere to the action.