Feldman and Indeterminacy in Music

I was doing some research on Morton Feldman, the composer who wrote the Rothko Chapel piece, and I found some interesting information about the movement of several American composers in the 50s and 60s who explored similar things in their music. One of the most interesting aspects to these composers is their use of indeterminacy. Indeterminacy refers to the use of compositions that allow for considerable interpretation and freedom to performers. Often, this freedom is introduced by chance as the performer is intended to somehow randomly select how a work is played.  For example, some pieces like Henry Cowell's Mosaic Quartet allows performers to play a series of fragments in a number of different orders. Perhaps the most extreme version of indeterminacy is John Cage's 4'33", which Mrs. Quinet discussed and which consists of 4 minutes and 33 seconds of rest. These sorts of works explore many postmodern concepts like the nature of art and composition and the subjectivity of music. Morton was closely associated with these and other composers, so I think this helps contextualize the very modern sounding work we listened to in class.