Dozens of mask-wearing music enthusiasts gathered at a church in an eastern German town on Saturday to witness the first note change in seven years in the world's longest lasting pipe organ performance.
The Saint Burchardi Church in the city of Halberstadt started playing "As Slow as Possible" by US composer John Cage in 2001 and the last note change took place in 2013.
The church is taking an extreme interpretation of the composition's title: the piece is expected to last 639 years, coming to a painfully slow end in 2640.
Sand bags were attached to the organ on Saturday, which coincides with what would have been Cage's 108th birthday, setting it to play G sharp and E for the next 2,527 days.
"The sound from October 5 2013 until today, September 5, Cage's 108th birthday, is the longest uninterrupted sound," said Rainer Neugebauer of the John Cage Organ Project in Halberstadt.