for one finger

Morton Feldman: (...) years ago I had one of those very curious conversations you can have with Stockhausen, when he was writing all these big pieces like Gruppen and Hymnen and at that time I was writing very tenuous little piano pieces here and there. He would use that as a weapon against me. He would say to me, “Have you ever written a big piece, Morton? You must try it, it’s fascinating.” So I said, “And Karlheinz, what you have to try is to write a piano piece for one finger” (...)

Morton Feldman and Iannis Xenakis
In conversation