This is Energy Ladders, a piece that I recorded by triple-tracking myself playing an FM synthesis patch (the "twist" being that it has an extra cosine applied to the modulated signal) written in Pure Data.

I need a push to reactivate the music writing after having to spend all of my time on other things, so I'm doing this as part of #synthruary, one of those things where you wear yourself out trying to do a thing every day of the month.