Hmmm... I've tried to compose something, but I more likely make "covers", trying to add a specific look for my midis, for example a theme for...
Sanctuary Forest - I took a techno and made birds instead of bits, then some drums, bells and rock - to show the course of humanity evolving and taking all from the nature, etc...
Soundless Spire - I took an unreleased chrono trigger song "singing mountain" and made it sang by synthetised voice, like Kefka in ff6 said, "screaming in unision", with some organs and a bit arab-like addons...
Campana - Mozart in techno version. Bells, bells, bells. LOTS of bells. After all, Campana is a church capital in my game and in latin "campana" is "bell"...
Azimuth Tavern - Jazz variance of earthworm jim theme! Yay!