ATONALITY - Music that is absent a tonal center. Some of the music written by Arnold Schoenberg, Alban Berg, Anton Webern, et al, subscribes to the notion of atonality. The "Method of Composing with 12 Tones" was developed by Schoenberg.

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atonality technique of music written by Arnold Schoenberg
atonality technique of music written by Alban Berg
atonality technique of music written by Anton Webern
atonality is similar to Twelve-tone method
atonality has opposing concept modern tonality