I *think*. I'm still testing it out. I'm just starting this, I *thought* it played a new one, but it was with similar music (and I wasn't really paying attention to it like I am now).
The game didn't freak out with changing the 74 to a 78 and adding 4 new entries at the bottom. So that's a good sign.
As far as just changing names in the SoundsMusic file, that part 100% works. So far I've tried mp3s and waves and it didn't have a problem.
I'll try to update with new info, if it comes up.
I think I'll test it with putting Slayer songs in place of the originals, and see if it plays anything else. Seems like a good test to me. (a might loud perhaps)