Having no allegiance to tonality; not having a key. In atonal practices, ordinary theories of consonance and dissonance have no force. One speaks of certain works of Liszt and Debussy as being nearly atonal; it was probably Schoenberg who most carefully worked out the musical possibilities of atonality. Twelve-tone and serial practices are a highly organized form of atonal composition.
Music from the Twentieth Century that does not use traditional chords or melodies. The primary composers of atonal music were Schoenberg and Berg. ( Lesson 35)
Music that is not in any specific key, usually sounds foreign to most people.