In the Burchardi Church in Halberstadt, an organ is playing John Cage’s piece ORGAN²/ASLSP, as slow as possible. The performance began on 5 September 2001 with a pause. The first pipes sounded about two years later. The performance is planned to end in 2640, after 639 years. The length counts back to 1361, when Nicolaus Faber completed an organ for Halberstadt Cathedral. The years from 1361 to 2000 are 639. The sound changes on dates fixed in advance. The most recent change came on 5 August 2026, and the next is scheduled for 5 October 2027. The foundation that runs the project has no institutional funding and relies on donations.