Here is my take on the problem: Yes, the music folder will be (or even is now) a bunch of unrelated files, that isn't sorted properly. But most users will never ever look into this folder and just include whatever music files they get with the pack downloads (at least I hope so). So a bit of chaos there doesn't really matter.
Actually it's the same as with the pieces in the "special" folder: As long as there are no name clashes (and for this reason we encourage to put the designer's name in front of the piece/music), it doesn't really matter how unorganized it is.
Basically the only way to keep all folder neat and sorted is the way Lix goes: Everything has to be approved by Simon and then added to the default release. But as soon as one opens the possibility for users to include stuff without Nessy or me checking it first, there will be chaos at some point. Of course one can try to minimize it, as we did with level packs and full styles, but music is somewhat less important: No level breaks, if the (correct) music file is missing.
So before changing anything, I would like to have one question answered: What are the big advantages of having a nicely ordered music storage, that pays off the non-trivial amount of coding work needed for any such solution?