Originally posted by HackerOfTheLegend
When I did that and then opened my ROM to test it in 1-1, the game froze.
Make sure you don't overwrite the samples for that song in particular. You gotta do some fancy footwork with inserts.
Follow this (unfinished detailed music data chart thing):
x0E0200 - Athletic Samples (5788 bytes)
x0E189C - Athletic Music (3363 bytes)
x0E25BF - Bonus Challenge Music (2170 bytes)
x0E2E39 - Kamek's Taunts + Boss intro + Mini-boss Music (3225 bytes)
x0E3AD2 - Cave Music (1470 bytes)
x0E4090 - Ending Samples (32092 bytes)
x0EBDEC - Ending Music (5394 bytes)
x0ED2FE - Forest/Jungle Music (1234 bytes)
x0ED7D0 - Flower Garden Music (3241 bytes)
x0EE479 - Forest/Jungle Samples (2572 bytes)
x0EEE85 - Flower Garden Samples
x0F00C1 - Final Boss Samples
x0F225D - Final Boss Music
x0F35F0 - Intro/Welcome to Yoshi's Island Music
x0F4322 - Default Music (includes map songs)
x0F5E48 - Kamek's Taunts + Boss intro + Big Boss Music + Boss victory (Maybe pre-boss is in this upload too?)
x0F705A - Castle Samples
x0F84E6 - Default Samples
x0FFEB2 - Castle Music (1680 bytes)
x100542 - Title/Story Music and Samples (+ SPC routines and SFX and stuff)
x10B5FA - End of all used music data
x110200 - End of allocated space for all music data
All of these pointers come one right after the other, and when you insert songs, try to make sure you don't overwrite necessary music data i.e. title screen music. IF you want to know how many bytes a section is, subtract the pointer from the next pointer in front of it.
I wonder what a HFD opcode would do in ASM...