THE world’s slowest concert, which is scheduled to take 639 years, picked up pace yesterday when a new chord echoed from the organ in an abandoned church in eastern Germany.

Conventional wisdom — that the opera is not over until the fat lady sings — has been turned on its head by the concert in the Saxon town of Halberstadt. “Here the question is whether the concert is over when the organist dies, or when the organ falls apart,” said Georg Bandarau, of the John Cage Organ Foundation. He was posing one of the riddles thrown up by a recital due to last more than six centuries. Will there, for example, be an encore? The work, written by the US experimental composer John Cage, was originally intended as a 20-minute piece for piano. He transcribed it for the organ and titled it Organ 2/ASLSP, standing for as slow as possible. But how slow is slow? A congress of musicologists decided that, in theory at least, a slow piece could last for infinity. Halberstadt proposed 639 years and that seems to have been the best offer.

In 1361 Nicolas Faber built an organ in the Saxon town that helped to revolutionise church music. That was 639 years before the Cage project. By separating out the chords of the 20-minute piece the musicians managed to create a blueprint for the longest performance in history.

Since the concert began on September 5, 2001, with an 18-month silence, fans of experimental music have been flocking to the church. Indeed, the little town is booming as a result. “Ten thousand people a year now come here to listen to the music and see the new organ take shape,” Herr Bandarau said.

At that rate Halberstadt should be able to welcome its millionth music lover sometime in the middle of the 22nd century, when the piece has reached the second section of the score, which has been divided into nine sections, each lasting 71 years.

Cage died in 1992 but loved the idea of playing with time — and shocking his audience. “If my work is accepted,” he said, “I must move on to the point where it isn’t.” In 1952 he staged his most notorious piece, 4’33”. The players sat silently for the allotted time.

Yesterday marked a chord shift. The 18-month silence was broken by the first chord in February 2003 — G-sharp, B and G-sharp. That was followed in July 2004 by two additional Es, an octave apart. Now the first chord has progressed to a second, comprising A, C and F-sharp, which will be held down until 2012 by sandbags placed on the organ. The next change comes with surprising speed, on May 6 this year, when the two Es are released.

The organ is being specially built for, and during, the concert. The organisers hope that enough money will be raised to fund new pipes in time for forthcoming new notes.

The half-time interval is planned for the year 2319.

ART OF NOISE

Iannis Xenakis used mathematical laws and formulas to compose his music. His first important work, Metastasis for Orchestra, was inspired by Einstein’s concept of time