The first three notes of the slowest/longest piece ever written was being played on a German organ this week. It’s written to last 639 years. “The three notes, which will last for a year-and-a-half, are just the start of the piece, called As Slow As Possible. Composed by late avant-garde composer John Cage, the performance has already been going for 17 months – although all that has been heard so far is the sound of the organ’s bellows being inflated.”