System of comp. in which all 12 notes within octave (7 white and 5 black notes of pf.) are treated as ‘equal’, in an ordered relationship where no group of notes predominates as in major/minor key system. One of first, if not the first, to devise such a system was J. M. Hauer, but it is generally assoc. with Schoenberg, whose ‘method of composing with 12 notes which are related only to one another’ was developed gradually 1920–5 and first used by him partially in his Op.23 and Op.24 (the 5 Piano Pieces and Serenade) and throughout his Op.25 (the Suite for pf.). In the Schoenberg method, all pitches are related to a fixed order of the 12 chromatic notes, this order providing the work's basic shape. The fixed order is called a note‐row (or series or set). No note is repeated within a row, which therefore comprises 12 different notes and no other. The note‐row is not a theme but a source from which the comp. is made. It can be transposed to begin on any of the 12 pitches, and it may appear in retrograde, inversion, and retrograde‐inversion. Since each of these transformations may also be transposed, each note‐row can have 48 related pitch successions. Schoenberg's foremost contemporary disciples were Berg and Webern, but it should be noted that their application of his theory differs considerably from his own, particularly in the case of Webern, who explored the possibility of ‘cellular’ comp., i.e. self‐contained structures within the note‐row. From his type of serialism, later composers progressed to total serialism.
Certain composers, e.g. Dallapiccola, Frank Martin, and Stravinsky, have used 12‐note technique but have retained not only their marked individuality of style but a relationship in their work to the major/minor system of tonality. Other composers who do not subscribe to Schoenbergian tenets have used all 12 notes without repeating any one note. Examples of this are to be found in Walton, Britten, Hindemith, and Shostakovich.
Argument will no doubt continue about which composer was the first to use 12‐note technique. Medieval candidates may be found, and Scriabin's ‘mystic chord’ is a pointer. Hauer's system pre‐dated Schoenberg's; and the Ger. critic Herbert Eimert has written that Jef Golyscheff comp. ‘the first unequivocal 12‐note music’ in 1914.