Ben Harper was a busy man at Bonnaroo. Besides his own Sunday set, Harper turned into a guitar hero during Friday night's SuperJam: Teaming with ?uestlove from the Roots and John Paul Jones of Led Zeppelin, Harper flexed some guitar muscle that was the talk of the festival on Saturday morning. After snapping a few shots for Spin's Bonnaroo photo shoot, Harper sat down in our tent to talk summer festivals (Pearl Jam fans: listen up!) and his long love affair with not just music, but the instruments themselves.