In 1985 John Cage composed the work ASLSP, with the instructions that it should be played As SLow aS Possible.

Two years later, he worked on a piece for organ. The score is eight pages long.

Gerd Zacher prepared a version that is twenty-nine minutes long. The directions given by Cage, who was present in the auditorium, were that it should be played like ‘a gentle morning’ and that at the end ‘it should disappear’.

Years later, a conference of musicians, theologians, and philosophers came to the conclusion that the longest possible time is that of the useful life of an organ, or until the harmony of a society breaks down.

And for this new performance, the town of Halberstadt was chosen because that’s where the first modern organ was constructed in 1361. The first one with twelve notes per octave (which suggests that the space of music opened up before that of painting).

The concert began on 5 September 2001. Six days before the Twin Towers fell. It will continue for 639 years, seven more than it took to build Cologne Cathedral.

Each movement will last for seventy-one years.

As in Beethoven’s Symphony No. 5, the first note of ASLSP is a rest.

Luis Sagasti, A Musical Offering, translated by Fionn Petch