I had no idea either, but here's the soundtrack:
Nobunaga No Yabou: Gameboy Ban (gameboy rip) (
http://rapidshare.com/files/310849691/NA_Game_Boy.rar)
I also found the MSX versions (I think so anyway, they say MDX, not MSX), although I still don't even really know what that system is. It looks like they are the same games as the NES ones. If you really want them I can upload them, but it's the same stuff.
oh, that won't be necessary if they're just the same ^^
Jesse, that OST sounds different than the game I have (Lord of Darkness).
Same music, but definitely a different sound. Perhaps it's the Super Famicom version?? -_-