It's a pretty simple formula. Take Discord, add funk rock, and you get awesome. I'm talking, of course, about the amazing fan song Discord (original here), which is one of my favorite pieces to come out of the MLP:FiM community.
Well, Thunder Dash took the inspiration of Discord and covered it in a funk rock style. The combination is fantastic. Give it a listen! There's also a midi version.
Thanks as always, Thunder Dash!