Composers count themselves lucky when musicians continue to perform their music after their death.

But the American avant-garde composer John Cage, who died in 1992, never would have guessed that a single performance of his music would begin in 2001 and still be playing. In fact, it isn’t due to conclude for another 616 years.

In a marathon performance like this, any little change becomes big news. On 5 February, 2011, for instance, one of the first three notes stopped sounding – after being sustained for eight years.

On 5 February, 2024, another note is going to begin playing – the first since Feb. 5, 2022. This one will be relatively short; it will hang around for only the next two years.

The piece is called Organ2 /ASLSP.

“ASLSP” refers to the phrase “as slowly and softly as possible,” a reference to a quotation that appears near the end of James Joyce’s novel Finnegans Wake – “Soft morning city! Lsp!”

Originally written for piano in 1985, Cage made an arrangement for organ. Like the piano score, Cage never specified how long the...