REQUEST: Metroidquest's World of Ruin Song Patch

I personally won't take the song from his hack and make a ips patch, but I can try to help you do it since you seem to be having problems with that.

This is the address of the song in question:
C9AC51 C9AE9E SPC No 3.05 - Dark World (4F)
or...
C9AE51 C9B09E, if it's headered.

If you open up the hack in a hex editor and go to C9AE51 you will see the song data there, it should look all modified compared to the original song data of Dark World. Compare with a clean ROM if need be to make sure. Now you want to dump that data, from C9AE51 to C9B09E (depending on the header this may change to C9AE51 to C9B09E. Dump that and inject it to the same place (Dark World) in your ROM. That's it for the song data. For the instruments you should use JCE's SPC editor in the tool section to make it easier. Again, use the Eternal Crystals hack as a reference and look at Dark World's instruments, and copy them to your ROM. Mission accomplished.

If you cannot get it still or need further assistance, please explain in detail what problems you are having.