Post-tonal Music Theory - Overview

Overview

In the latter part of the 19th century, composers began to move away from the tonal system. This is typified in Richard Wagner's music, especially Tristan und Isolde (the Tristan chord, for example). Arnold Schoenberg and his pupil Anton Webern proposed a theory on the emancipation of the dissonance to help analyse the general trend and, in particular, their own atonal music. Composers such as Charles Ives, Dane Rudhyar, and even Duke Ellington and Lou Harrison, connected the emancipation of the dissonance with the emancipation of society and humanity.

The basic idea is that as time progresses, the ear becomes acclimatised to more and more complex sounds. This happens not just for individuals but also for societies as they start to write more complex music. Consonance and dissonance become indistinct from each other: dissonances slowly become heard as consonances. Jim Samson explained it this way: "As the ear becomes acclimatized to a sonority within a particular context, the sonority will gradually become 'emancipated' from that context and seek a new one. The emancipation of the dominant-quality dissonances has followed this pattern, with the dominant seventh developing in status from a contrapuntal note in the sixteenth century to a quasi-consonant harmonic note in the early nineteenth. By the later nineteenth century the higher numbered dominant-quality dissonances had also achieved harmonic status, with resolution delayed or omitted completely. The greater autonomy of the dominant-quality dissonance contributed significantly to the weakening of traditional tonal function within a purely diatonic context."