<P> Arnold Franz Walter Schoenberg or Schönberg (/ ˈʃɜːrnbɜːrɡ /; German: (ˈaːʁnɔlt ˈʃøːnbɛʁk) (listen); 13 September 1874--13 July 1951) was an Austrian composer, music theorist, and painter . He was associated with the expressionist movement in German poetry and art, and leader of the Second Viennese School . With the rise of the Nazi Party, Schoenberg's works were labelled degenerate music, because they were modernist, atonal and what even Paul Hindemith called "sonic orgies" and "decadent intellectual efforts" (Petropoulos 2014, 94--95). He emigrated to the United States of America in 1934 . </P> <P> Schoenberg's approach, both in terms of harmony and development, has been one of the most influential of 20th - century musical thought . Many European and American composers from at least three generations have consciously extended his thinking, whereas others have passionately reacted against it . </P>

– composer arnold schoenberg was highly influential in the movement called –