Music editor (filmmaking) Information
Among the music editor's roles is creating a "temp track", which is a "mock-up" of the film's soundtrack using pre-existing elements to use for editing, audience previews, and other purposes while the film's commissioned score is being composed. 
- Ronald H. Sadoff (2006). "The role of the music editor and the 'temp track' as blueprint for the score, source music, and scource music of films". Popular Music. Cambridge University Press.