In the year 2000, in a small east German town, work began on the construction of an organ that had one purpose: to perform John Cage’s ORGAN2/ASLSP (1987) for precisely 639 years. The late avant-garde composer had instructed the piece to be played ‘As Slow As Possible’. And so in 2001 – the instrument finally ready – the world’s longest organ recital began in St Burchardi church, Halberstadt, with a rest lasting 17 months before the first chord commenced droning in 2003.