Length of World’s Longest Concert? 639 Years John Cage piece will reach its conclusion in 2640 By Kate Seamons, Newser Staff Posted Nov 22, 2011 8:40 AM CST 15 comments Comments Shiraz Art Festival: David Tudor (left) and John Cage performing at the 1971 festival. (Photo courtesy Cunningham Dance Foundation archive) (Newser) – You can currently catch a performance of John Cage's "Organ²/ASLSP(As SLow aS Possible)" in Halberstadt, Germany—and your great-great-great-(OK, do that 15 more times)-grandchild will be able to catch the end of it. The Washington Post takes a look at the most unusual concert, currently in its 10th year and scheduled to end in 2640. Cage himself did not pick that end-date; 639 years is the length of time between the construction of the first church organ and the 2001 start of his performance, which coincided with Cage's 85th birthday. The score, which would total 29,289 miles, is being played by an automated organ housed in the former St. Burchard church. And it's being played slowly. Chord changes happen so sporadically that the next one isn't scheduled to occur until July 5, 2012; a 2008 note change drew 1,000 listeners. And 2008 was also the year that more pipes were added to the organ—the progression is so slow that the concert began before the instrument had been completely built. Want your own piece of history? You can sponsor a note for an entire year (the year of your choosing) for a minimum donation of about $1,350. Click to hear the current sound, or click to read more from the Post.