If a cue is labelled as ‘Polaroid’, then it is a musical sketch, for demonstration purposes only.
Music cues are made initially as these ‘Polaroids’, until all have been finished to the Director’s satisfaction. The music mixing session then takes place, to bring all music cues to glorious cinematic life.
Some composers waste time making ‘Polaroids’ sound like the finished product, early in music production. That’s like making architects’ plans and computer-renderings with cement. While doing this may delight a director temporarily, it impinges on composition time which might otherwise have been spent making the score finer in the long-term for the Director’s film.
A ‘Polaroid’ music track may necessarily use slightly weaker-sounding, ‘place-holder’ sounds, before the music mixing session. Without wasting time, the composer will take steps to make the ‘Polaroid’ version resemble the final mix as far as possible at that longer, early stage. Leaving the mix to the end in this way, optimizes music production time.
Once music is ‘mixed’ it becomes locked to an extent and more laborious to change. Rest assured: music mixes can also be tweaked during the mix after all ‘Polaroids’ have been approved.
The ‘Polaroid’ (before mix):
Finished Music Cue (after mix):