Twelve

note composition -composition by the use of the twelve semitones of the octave in a predetermined order or series, which may be inverted, written in retrograde form or in retrograde inversion, and transposed. The system of composition, developed by Arnold Schoenberg in the early 20th century, has had a strong influence over the course of music of the 20th century (see serialism)tone music -music in which no pitch class (or note) is repeated until all other chromatic pitches have been used. any group of twelve pitches arranged this way is called a rowtone technique -series of the twelve half-steps of the octave with each given equal importance. All twelve must be used before the series can begin again. This gives the music the effect of no tonal center