Try removing the custom stage that replaces Mushroomy Kingdom, then play on it to rule out if it is the rel or not
- I can't tell if the song from Super Mario Land freezes or not, since I cannot alter how often a song plays anymore..
Use the My Music Reset code.
Mushroomy Kingdom (Above and Below) My Music Reset :
* 4A000000 9017EC6C
* 14000000 00002714
* 14000004 00000432
* 14000008 00002723
* 1400000C 00000432
* 14000010 0000271D
* 14000014 00000432
* 14000018 00002715
* 1400001C 00000532
* 14000020 00002716
* 14000024 00240532
* 14000028 00002717
* 1400002C FFFF0532
* E0000000 80008000
Remove it after it works.