AsSLowASPossible

In 1985 John Cage composed ASLSP, a work for the organ whose directions are to play it as slow as possible. It's first performance lasted 29 minutes... a more recent performance was 71 minutes. But is that really as slow as possible? No!

Since September 5, 2001 there is an ongoing performance of the piece in Halberstadt, Germany that is intended to last 639 years. The significance of the date, location, & duration is that September 5th was the 89th anniversary of John Cage (and the year of the start of the millenium), the organ is located in the birthplace church of the modern organ, and the performance started on the 639th anniversary of the modern organ.

The computer-controlled performance began with 1-1/2 years of silence (due to the work's first initial notes being rests).

http://www.npr.org/programs/pt/features/2003/sep/aslsp.html
http://www.john-cage.halberstadt.de/new/index.php?l=e