Temp music is a song used as a guideline when editing
Temp music is a song or instrumental that is used as a guideline for mood or atmosphere in the editing phase of a film or tv production. Most of the time, it will be replaced with an original work before the production is completed.
An example of the use of temp music is David Fincher during the production of the movie The Social Network (2010). He used instrumentals from Nine Inch Nails’ album Ghosts I-IV to score the movie during editing. He liked the music so much that he decided to hire Trent Reznor to create the final score for the film. The score went on to win numerous awards, including a Golden Globe and an Oscar, and began Reznor’s career as a film composer.