ShareHALBERSTADT, Germany (AP) — A small organ in eastern Germany is the headliner of the world’s slowest concert. It has been playing the same piece of music by composer John Cage at a glacial pace for nearly 25 years. The organ, center, of the John Cage Organ Project Halberstadt is illuminated prior to a chord change of the organ inside the medieval Burchardi Church in Halberstadt, Germany, Wednesday, Aug. 5, 2026. Organ builder Johannes Huefken works on organ pipe for the John Cage organ project at his work shop in Halberstadt, Germany, July 6, 2026. (AP Photo/Matthias Schrader) Organ builder Johannes Huefken works on organ pipe for the John Cage organ project at his work shop in Halberstadt, Germany, July 6, 2026.