Twelve-tone technique is a method of musical composition

Musical composition

Musical composition can refer to an original piece of music, the structure of a musical piece, or the process of creating a new piece of music. People who practice composition are called composers.- Musical compositions :...

 devised by Arnold Schoenberg

Arnold Schoenberg

Arnold Schoenberg was an Austrian composer, associated with the expressionist movement in German poetry and art, and leader of the Second Viennese School...

. The technique is a means of ensuring that all 12 notes of the chromatic scale

Chromatic scale

The chromatic scale is a musical scale with twelve pitches, each a semitone apart. On a modern piano or other equal-tempered instrument, all the half steps are the same size...

 are sounded as often as one another in a piece of music while preventing the emphasis of any through the use of tone row

Tone row

In music, a tone row or note row , also series and set, refers to a non-repetitive ordering of a set of pitch-classes, typically of the twelve notes in musical set theory of the chromatic scale, though both larger and smaller sets are sometimes found.-History and usage:Tone rows are the basis of...

s, an ordering of the 12 pitches. All 12 notes are thus given more or less equal importance, and the music avoids being in a key

Key (music)

In music theory, the term key is used in many different and sometimes contradictory ways. A common use is to speak of music as being "in" a specific key, such as in the key of C major or in the key of F-sharp. Sometimes the terms "major" or "minor" are appended, as in the key of A minor or in the...

. The technique was influential on composers in the mid-twentieth century.

Schoenberg himself described the system as a "Method of Composing with Twelve Tones Which are Related Only with One Another".