from last night, here's my attempt at visualizing the smb2 music engine and how it reads data.
@Xkeeper I wonder what happens if you just copy/paste the music data between them
I havent checked the SMB2 code but in z1 essentially there's a song definition that says "these subsections in this order with this loop point" and then the subsections are either a note (which you look up on the frequency table) or a note length (also from a table)
The length of a "master" instrument's section determines when the section is over and everyone moves to the next
@atinyfairy probably changed a few numbers but somehow i wouldnt be surprised