My game works, and I quite like it, so I think I'm just going to spend the rest of the time on music.

I think David Lynch once said that a great secret for making good films — and I think it probably applies to games too — is to do the music first, and then listen to it and let it give you ideas. And when you make the final thing, the soundtrack will of course fit perfectly!

I think this is probably a good idea, and I'd like to try it sometime, but in Ludum Dare I always do the music last, because fiddling around in a DAW just expands to fill all available time.