Those are SPC files, and that particular example was one rip of Final Fantasy VI (III)'s soundtrack.
Unfortunately, it only handles music embedded in Super Famicom/Super Nintendo games. To convert your own music to SPC, you’d have to rewrite it for the SNES sound chip.
Everything filed under “Chiptune”, excluding the AT3 and MAB files which are effectively general purpose music formats, comes to 1.14 GB for 4211 items totaling 158:50:29. There are a lot of duplicates in there, because for a lot of these items it’s more trouble to hunt down a replacement copy than it is to store a backup.
The catch, of course, is that it’s all retro videogame music from bleep to bloop.