Now entering its third season, Comedy Bang! Bang!, which started as a humble podcast, has come into its own. And just in time, as next year the show will air 40 episodes. What’s a better way to celebrate than this clip from this Thursday’s episode, airing on IFC at 10:30, in which Zach Galifianakis sings host Scott Aukerman’s favorite tune, which, lucky for them, is in the public domain? Jenny Lewis sings backup. It’s just like the Postal Service, if the Postal Service sang about “Camptown Races” instead of eye freckles.