An aesthetic subversive who signed his name on a bottle-drying rack and called it "readymade" art. A composer who cast the rules of music to the winds in order to "let sounds be themselves." A maker of suicidal machines. An artist whose pieces incorporate real bedclothes and stuffed goats. A choreographer who delights in the prosaic and the awkward. With lively understanding and irreverent wit, distinguished art critic Calvin Tomkins deciphers the challenging-and sometimes mystifying-work of Marcel Duchamp, John Cage, Jean Tinguely, Robert Rauschenberg, and Cerce Cunningham.