By Steve Rosenberg
BBC News, Halberstadt, Germany
John Cage did not say how slow his piece should be played
A note from a piece by a US composer is to be played this weekend in a German town in what has been called the world's slowest and longest concert.
The church organ in Halberstadt will play the next - sixth - chord of John Cage's As Slow As Possible work.
The performance began in 2000 and is scheduled to last a total of 639 years.
The idea of taking so long to get through the composer's piece is to find a musical way of countering the hustle and bustle of modern life.
When Cage wrote his famous work in 1985, there was one tiny detail the late avant-garde composer chose to omit - exactly how slow the piece should be played.
Its maiden performance lasted a rather normal 29 minutes. A subsequent version took 71 minutes.
But at the medieval church in Halberstadt, they are really testing the patience of the audience.
Every so often - although not too often, you understand - a chord change is made on the church organ and the piece of music edges a tiny bit closer to the end.
This weekend, weights holding down the organ pedals will be shifted and the sixth chord change will occur, to much celebration in the town centre.
If only Halberstadt could find a way of countering growing old - at least then I might stand a chance of hearing the final note being played in the year 2639.