Arnold Schoenberg or Schönberg was an Austrian-born American composer, music theorist, teacher, writer, and painter. He is widely considered one of the most important and influential composers of the 20th century. Schoenberg created new methods of musical composition involving atonality, namely serialism and the 12-tone row. He was also one of the most influential teachers of the 20th century; among his most-significant pupils were Alban Berg and Anton Webern.