It's a Rare Note Change in Piece That Will Play Until 2640

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, and a historic moment occurred last week inside the medieval Burchardi Church, in Halberstadt, Germany. A rare chord change on Wednesday—from seven notes to eight—represented the completion of about 4% of the 639-year endeavor of the John Cage Organ Project Halberstadt, reports the AP. More than 150 people squeezed inside the church Wednesday to witness what was the piece's 17th chord change, with dozens more watching a livestream outside.

For three minutes, the crowd listened to the "old" chord with its seven pipes. Then, an eighth pipe was slotted into the small organ, bringing with it a new sound that reverberated throughout the church. The spectators listened for another three minutes—some filming with cellphones, others taking it all in with their eyes closed and heads bowed—before breaking out into applause and cries of "bravo!" "It's a very subtle difference," said Jeffrey Lependorf, executive director of the John Cage Trust in New York. "There's a higher sound that's a little more prominent."

Cage's only direction for this piece was to play it as slowly and as softly as possible. The piece will last 639 years, from 2001 to 2640, a time frame chosen as a tribute to a historic organ in Halberstadt that dates back to 1361, or 639 years before the project was initiated in 2000. The performance itself began Sept. 5, 2001—what would have been the 89th birthday of Cage, who died in 1992—with a silent pause that lasted until Feb. 5, 2003, when the first chords could actually be heard.

The composition, called "ORGAN²/ASLSP (As SLow aS Possible)," is scheduled to finish on Sept. 4, 2640. An electric-powered blower system sends wind into the organ to create a continuous sound. A chord change, done manually, means that the sound of the organ pipes changes either because new sounds are added or existing sounds end. The next chord change will take place on Oct. 5, 2027, when the overall sound will be reduced by releasing the E4 pipe. Inheritable "final tickets" for the Sept. 4, 2640, finale are already being sold for $3,045.