||Schönberg's musical output
Schönberg's artistic work can be divided into four periods. With the exception of the last they have an exemplary and historically representative character for the development of music in the 20th century.
1st phase: up to 1907 (late Romantic period)
His first creative phase that was still tonal ("Gurrelieder", Sextet for strings, "Verklärte Nacht" = "Transfigured Night"), continuing Richard Wagner and Johannes Brahms, led to a final intensification and differentiation of late Romantic musical style.
2nd phase: 1908 - 1921 (free atonality)
The late Romantic musical style is developed in the direction of a free atonality in the 1st Chamber Symphony op.9 and in the 2nd String Quartet op.10; it is fully developed in the George-Lieder op.15 (1908/09) and in the Piano Pieces op.11 (1909). This atonal expressionist phase includes the monodrama "Erwartung" ("Expectation") op.17, the 21 poems for voice and chamber ensemble "Pierrot lunaire" ("Pierrot by Moonlight") op.21 and as a complete novelty the Pieces for Orchestra op.16 and Little Piano Pieces op.19.
3rd phase: 1921 - 1933 (classic atonality)
After 1920 he began the 3rd phae with the definition of a new systematic principle, the 12-note technique. The late Romantic music was chromatised in the melodic horizontal as well as in the chordal vertical. Schönberg began to feel the rules of tonality as a severe restriction of his compository possibilities so that he finally severed his ties to the minor-major system. The breaking away from a tonal centre was first achieved in the 4th movement of his 2nd string quartet (1907), op.10. The 5 Piano Pieces op.23, the first twelve-note work, were only finished in 1923. This piece and the Serenade op.24 are to be regarded as a transition to a pure twelve-note compository technique.
The idea of the "method of composition with 12 notes related only to each other" filled Schönberg with such joy that he remarked to his friend and pupil Josef Rufer during a walk in summer 1921: "I have made a discovery through which the predominance of German music is guaranteed for the next 100 years."
The basic motive of Schönberg's efforts was, in his own words, to base the structure of his works "consciously on a unifying idea that would not only produce all further ideas but would also determine their accompaniment, the 'harmonies'." This will to condensate directs melodies and chords of a work according to a single twelve-note row. It is an extremely "tone-democratic" structure and sociologically it is certainly no chance that this system developed in a period of great social upheavals and revolutions.
4th phase: after 1933
The fourth (American) creative period comprises further partly modified twelve-note compositions, partly a reverting to tonality, partly serious philosophical and religious late works (psalms during his last years).
Consonance and dissonance in