ABSTRACT
Schoenberg's desire to present a clear and systematic music theory is most comprehensively exposed in the Harmonielehre. This chapter addresses different aspects of tonal structure in Schoenberg's thought. All tonal relationships are included in the monotonality of a tonal work; Schoenberg, however, also suggested that there is an abandonment of the principle of monotonality in modern works. One of the most intriguing notations in Schoenberg's tonal theory is the use of crossed Roman numerals to indicate transformed chords. These are chords altered by the introduction of substitute notes giving rise to chromaticism in one or more notes of chordal constitution. Schoenberg begins with the transformations on the II degree and then applies these to the remaining diatonic triads. In transformations, the substitute notes are considered to have another level of importance, different from roots in a diatonic context, and thus assuring a clear tonal relationship to the tonic.
