I was always advised against listening to music while developing film by a Lecturer at University

He had found that students agitated their films in tune with the music - easy listening melodies = gentle agitation all the way up to death metal = very vigorous agitation.

If you are consistent in your music choice then it doesn't matter.

I knew someone who set up on a tape cassette with the times overlaid onto a set of music tracks - initially it worked great but the repeated listening to the same few songs again and again and again caused him to drop the idea.

Martin