How does Schoenberg's twelve-tone method work, and why did it divide listeners?

The twelve-tone method is a way of writing music so that no note is the "home" note. It ensures that all 12 notes of the chromatic scale are sounded about equally often, avoiding emphasis on any one note, by using a tone row: a specific ordering of all twelve notes, with no note repeated within the row. Josef Matthias Hauer first devised the technique, publishing his "law of the twelve tones" in 1919, and Arnold Schoenberg developed his own, better-known version in 1923.

Why bother? Schoenberg meant the technique to replace the structural differentiations that tonal harmony used to provide. Rudolph Reti put the fundamental idea in one line: replace one structural force, tonality, by another, increased thematic oneness. The row is the raw material for the pitches, and it may appear in its prime form, inverted, in retrograde (backwards), or in retrograde inversion. With transposition to any of twelve starting notes, a row has up to 48 forms. Duration, dynamics and other aspects of music remain free for the composer to choose.

There is a common misunderstanding about the rules: they govern how the row is built, and do not mean that no note can repeat until all twelve have sounded.

The divide was between experts and the wider public. Schoenberg's music was already causing uproar before the method: at the "Skandalkonzert" of 31 March 1913, police intervened during audience brawls. Afterwards the method won over composers. By the 1950s it was widely used, and even former opponents such as Copland and Stravinsky adopted it. The public was another matter. In 1977 Christopher Small observed that many music lovers still found Schoenberg's music difficult, and Ben Earle found in 2003 that he remained revered by experts but unloved by the public. Schoenberg had hoped that grocers' boys would one day whistle serial music; as the musicologist Nicholas Cook puts it, that day never came.