Harmony in Expressionism

Instead of the seven-step scale of traditional tonality, we have here the twelve-tone technique or dodecaphony, where all 12 pitches of the chromatic scale are considered equal. The way for composers to organise this material is to devise a tone row determining the order of the 12 pitches. The basic rule in using this technique was that every pitch had to be used, in order, before any of them were repeated. The purpose of this was to prevent the ear from perceiving any note as the tonic, or fundamental pitch.