Go to the vault and download the brstm's there. If you want custom music that's the place to get it. Brstm's go inside pf->sound->strm. If you're saying you want to jumble the music up into one random mess then I don't think that's possible. Also if you want to make your own brstm's you'll need a brstm maker which you can find via the search feature.
What I want: The most direct and clear desciption is...
A differnt song for each stage.
evanescence for battlefield.
nickelback for animal crossing.
swimming with dolphins for final destination.
the starting line for jumble falls.
Just pre-designated songs for certain areas. not a 100% chance to hear the song because each stage has more than one song on it, but I still have a chance of hearing that song when that stage is chosen.
Is there any way for this to happen? I saw a video on youtube once ad he had drop it like its hot by snoop dog for his battlefield..