Arnold Schoenberg (1874-1951) was an Austrian-American composer, music theorist, teacher, writer, and painter. He is widely considered one of the most influential composers of the 20th century. He was associated with the expressionist movement in German poetry and art, and leader of the Second Viennese School. As a Jewish composer, Schoenberg was targeted by the Nazi Party, which labeled his works as degenerate music and forbade them from being published.
Schoenberg's early works were in a late Romantic style, but he soon began to experiment with new musical techniques, such as atonality and serialism. His most famous works include the operas Erwartung (1909) and Moses und Aron (1930-1932), the orchestral pieces Pierrot Lunaire (1912) and Five Orchestral Pieces (1909), and the chamber works Verklärte Nacht (1899) and String Quartet No. 2 (1908).
Schoenberg was a highly influential teacher, and his students included Alban Berg, Anton Webern, and many other composers who went on to become important figures in 20th-century music. He was also a prolific writer, and his writings on music theory and composition are still studied by musicians today.
Schoenberg's music was often controversial during his lifetime, but it has since been recognized as some of the most important and innovative music of the 20th century. He is considered one of the most important figures in the development of atonal and serial music, and his work has had a profound influence on composers of all genres.