Friday Night Funkin'
A spin-off to a bigger mod, a small thing to insert into your Psych Engine, and a demo for a lil' Mario Mod, and they're all one song each.
Play for yourself:
https://gamebanana.com/mods/534138 (FREAKPOSTOR)
https://gamebanana.com/mods/528041 (Turnabout)
https://gamebanana.com/mods/534813 (SMW: Power Star Melody Demo)