Twelve-tone technique is a method of composition devised by schoenberg in the 1920s that organises pitch around a fixed ordering of all twelve chromatic notes.
Arnold Schoenberg developed the twelve-tone technique (also called dodecaphony or serial music) around 1921–1923, presenting it publicly in his Suite for Piano Op. 25 (1923). The composer first sets out a 'tone row' — an ordering of all twelve pitches of the chromatic scale, each used exactly once. The row may then be transposed, inverted, played in retrograde, or in retrograde inversion, providing a fixed but flexible structural foundation. Webern compressed the technique into miniatures of crystalline economy; Berg used it more freely, smuggling tonal hints into 'Lulu' (1937) and the Violin Concerto (1935). After 1945, Pierre Boulez and Karlheinz Stockhausen extended serial principles to rhythm, dynamics, and timbre — total serialism. The technique has been one of the 20th century's most influential and contested ideas, shaping composers as different as Stravinsky, Copland, and even film composers like Bernard Herrmann.