The hardest song that I can play on drums would probably be Tom Sawyer by Rush. Though for some reason, the instrumental part of Helter Skelter always messes me up. I don't really play guitar. I think I can play the riff to Sunshine of Your Love, and Smoke on The water, lol. As for bass, I'm trying to learn My Generation by The Who. That bass line is pretty difficult. Well thats it for me.