It's Dastardly Spike! (old-timey Western piano chords)
First off, I want to apologise to all the Pinkie Pie fans for tying her up like that, but she's the only pony suitable for this role. It also stops her from singing show tunes that causes two sides of civilisation to go to war between each other.
(I've also been playing a lot of Red Dead Redemption lately, so maybe there's that too.)