John Cage: Organ playing 639-year-long piece changes chord
The longest – and slowest – music composition in existence had a big day on Monday – it changed chord for the first time in two years. Crowds gathered at a church in Germany to witness the rare moment, which is part of an artistic feat by avant-garde composer, John Cage. The experimental piece, entitled As Slow as Possible, began in 2001. Being played on a specially-built organ, it is not set to finish playing until the year 2640.
YouTube video of the chord change.
Although not the longest piece in existance. Longplayer is set to last a millennium, for example.