This thesis alms to identify and explore the ideas of John Cage, then looks at their impact on and absorption by a variety of American composers. This in turn provides the context for my own compositional work which forms the main substance of this submission and which is presented on compact disc (accompanied by indicative scores). The source material for the second half of the thesis comes largely from my own book of interviews with composers, American Originals (co-authored with Nicola Walker Smith), which is included as an appendix.