Outsider music: classics of American classical music (46) - Morton Feldman - Rothko Chapel (1971) Morton Feldman ~ Rothko Chapel Another important and bizarre modernist American composer, he was part of Cage's circle, but he distinguished himself for composing absolutely original music, based on isolated and lengthy sounds. Famous is the "Fantozzian" duration of some of his pieces, like the second Quartet which exceeds 5 hours.