Today (Sept. 5 2020), the ongoing Halberstadt performance of John Cage’s As Slow as Possible will change notes! The last note change was in 2013. The performance began in 2001 and is designed to last for 639 years, until 2640.
An immortal organist is not involved. Weights are placed on the pedals of an organ designed exclusively to perform the piece, and are moved now and then as the score dictates. Organ pipes are added or removed as needed.
“On the dates of the sound changes the church is usually well visited.”