There is no louder sound in the musical realm than a pipe organ at full throttle. According to Guinness World Records, an outdoor organ constructed for Expo 2012, in South Korea, has produced tones measured at 138.4 decibels, exceeding levels recorded in the nineteen-seventies at performances by the likes of Led Zeppelin and The Who, and rivalling the noise generated by a jet engine on the tarmac. +