I have two questions about alternate playable tracks, particularly in conjunction with this GB Player patch that I'm using in my hack. They're very different, so it might take more brainpower to get them answered properly.
DISCLAIMER: I really don't know what I'm talking about when it comes to assembly code. All I can do is assemble it and insert it, along with change a few pointers within it.
Technically, if you called the variable music switcher first, then called mine, it would work, but there's more to it than that since mines relies on specific code changes at positions in the ROM which would conflict with the variable switcher.
I inserted jingles and they worked fine. So that's odd.