Canadian musician and producer Gonzales set the world record for longest solo piano performance today, AFP reports, clocking in at 27 hours, 3 minutes, and 44 seconds. The harrowing performance incorporated 300 musical pieces, from Britney Spears to Beethoven. Gonzales was allowed a 15-minute break between three-hour sets, and 30 seconds to rest between songs. (More Guinness World Records stories.)