As Slow as Possible is a musical piece by American avant-garde composer John Cage, who deliberately neglected to specify how slowly it should be played. Piano performances of the score usually last from 20 to 70 minutes. However, a performance that began in 2001 at a church in Germany is still going on and is expected to continue until 2640. The church’s organ continuously emits the low hum of a chord that began several years ago. When will the next note-change occur?
Source: The Free Dictionary