I found a sweet store online where you can buy old Japanese MSX and Sharp X68000 game music in mp3 format using Paypal... THIS CHANGES EVERYTHING!  https://www.amusement-center.com/project/emusic/

The music for Knight Arms and FZ Senki Axis is super doooooooooope

I need to find out how to find other stores like this!  It probably involves using Japanese characters in my search terms.  It is time to level up my Googlin skills.