(1874-1951) an Austrian COMPOSER who went to the US in 1933. He invented the "twelve-tone system" of writing modern music, in which music is written around a set of twelve notes of a CHROMATICSCALE . His system has influenced many modern COMPOSERs. His works include Transfigured Night, Pierrot Lunaire, and an OPERA that he did not finish Moses and Aaron .