This organ will play one composition until 2640. It's redefining how slowly music can be played

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.

A rare chord change on Wednesday — from seven notes to eight once an A4 pipe is added — will represent the completion of about 4% of the 639-year endeavor of the John Cage Organ Project Halberstadt.

While the project commenced in 2000, the performance began Sept. 5, 2001 — Cage's 89th birthday — with a silent pause that lasted until Feb. 5, 2003, when the first chords could actually be heard inside the medieval Burchardi Church in Halberstadt, Germany.

The “ORGAN²/ASLSP (As SLow aS Possible)” composition 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.

On Tuesday, Jeffrey Lependorf, executive director of the John Cage Trust in New York, said he was looking forward to comparing the difference between the sounds before and after Wednesday's chord change.

“You feel it through your whole body,” he told The Associated Press. “It resonates in this incredible way.”

Cage, an American avant-garde composer, was born in Los Angeles in 1912 and died in New York in 1992. He was also a renowned music theorist, artist and philosopher whose only direction for this piece was to play it as slowly and as softly as possible.

The interpretation of the composition in Halberstadt has resulted in the smallest unit being one month long. Other units — as well as silences — can last years.

The project has transformed the Burchardi Church, which was left largely in ruins before money was raised for a new roof and other fixes to make the piece a reality. The sound there envelopes visitors throughout the church and gives them new experiences to hear as they move through the empty space.

“I think it really is the organ playing the church and not the other way around,” Lependorf said. “You move two inches in any direction and it sounds not subtly different — very different.”

The piece will last 639 years, from 2001 to 2640. The time frame was chosen to be a tribute to a historic organ in Halberstadt that dates back to 1361, or 639 years before the project was initiated in 2000, according to Anneli Borgmann, chairwoman of the John Cage Organ Project Halberstadt's board of trustees.

The time frame allows the project's stewards and visitors to contemplate not only Cage's legacy but their own as guardians of the organ and its sounds. They also wonder what the world will look like by the end of the piece — will the church still be standing? Will the city of Halberstadt, which has already lived through two world wars, survive climate change?

The organ, at least, is built to last.

Organ builder Johannes Hüfken said the pipes he's crafted for this will last at least another 500 years.

“This John Cage project is a good example of thinking ahead for the next generation — thinking outside the box, beyond the completely normal and traditional,” he said.

Wednesday's event will mark the piece's 17th chord change. The next is set for Oct. 5, 2027, when the overall sound will be reduced by the E4 pipe.

Inheritable “final tickets” for the Sept. 4, 2640 event are already being sold for 2,640 euros ($3,045).

Markus Schreiber contributed to this report.