Fantastic. Worked perfectly after multiple tries (i made some silly errors haha).
I just have one note, if you're adding a new song and you overwrite an old pointer that you added and it's placed BEFORE the song table in the rom, the song WILL NOT play in game.
Like if song table is at 0x9D1000 and it points to a header at 0x850000, sappy will play the song, but it wont work in the game. But if the header is at 0xA50000 it works perfectly.
Another note, if you add extra songs, make sure you don't repoint them in a hex editor. It plays the song but there's a weird reverb effect if you do that.
Instead, when inserting the song, just change the header in sappy.
Would post pictures, but can't yet.
Perhaps you should add that into your tutorial, LinkandZelda.