Thank you for that video link and taking the time to reply. That looks like it might be a bit more in depth than the video I had available. I must have overlooked it because I didn't know GB Studio also used GBT-Player until now.
I think there might be a misunderstanding as to what I'm trying to do. I'm not looking for a music file made within the limits of a Game Boy's hardware, I need to use OpenMPT and that restrictive template file for GBT-Player because I'm making a Game Boy game meant to run on emulators and real hardware.
Importing MIDI files was how I made the two placeholder songs that are currently in my game.