It wouldn't, Wii/GC games have a common file; fst.bin which holds all the files and file sizes, if you were to replace a file that's of a different size the game may crash. This is just what I think anyways, but music would always get stuck without reaching the end or begin looping, and this would only work by rebuilding the fst file.Too bad Dolphin doesn't support FST, that would make Brawl modding so much easier, but I digress.