u/Excellent-Hat305

I thought that the music in the GBA version sounded weird and didn't match the usual sound of the GBA sound chip, and I discovered that's because they didn't actually replace the music hacking the roms, I think what they did was lowering the rom's music volume to 0% and playing the new music's audio files independently on top.

This means that if you were to extract the roms of the GBC and GBA games and play them on an emulator they would have the original OST, I'm not sure about the Jaguar and DOS versions, but I know for sure that the PSX version has the OST hacked/modded into the rom.