HALBERSTADT, 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. FILE - The organ of the John Cage organ project is illuminated prior to a 'sound change' at the Buchardi Church in Halberstadt, Germany, Sept. 5, 2020. “It’s a very subtle difference,” said Jeffrey Lependorf, executive director of the John Cage Trust in New York. (AP Photo/Markus Schreiber)Cage fan Michael Barnett, 55, from Glasgow, in Scotland, said attending the chord change was a bucket list item.