Gary his epic synthesizer battle in The Regular show. It's from episode 23 of season 7 called "Gary's Synthesizer"

The cool thing is that the synth Gary is using is based on a legendary range of synths by Keith Emerson, the Moog Modular synthesizer, and they got the sound pretty good too. It is actually in itself a pretty well put together synt composition/battle, this scene, if you ask me.