Arnold Schönberg (born September 13, 1874 in Vienna, Austria-Hungary; † July 13, 1951 in Los Angeles, California, USA) was an Austrian composer, music theorist, composition teacher, painter, poet, and inventor. He came from a Jewish family, emigrated to the United States in 1933 and took United States citizenship in 1941. After his emigration he wrote his name as Arnold Schoenberg.

Schöberg, along with Igor Stravinsky, is considered "one of the most influential composers of the early 20th century after Claude Debussy" and was the central figure of the Second Viennese School (also known as the Viennese Atonal School). Their efforts to think "tonality in its late Romantic manifestation consistently to its end" led to the twelve-tone technique after the abandonment of major-minor tonality between 1906 and 1909 and between 1904 and 1911, respectively. Around 1920, Schönberg developed the theoretical formulation of this new compositional technique in parallel with the less well-known Josef Matthias Hauer, which was later further developed into serial music and taken up by numerous composers of New Music. At the Villa Josef in Traunkirchen, Arnold Schönberg composed the first piece in the twelve-tone technique he had developed, the Praeludium of the Piano Suite op. 25, in July 1921.