ABSTRACT
This chapter focuses on the emerging vocabulary of the early and middle twentieth century, including Church modes, Pentatonic scales, Quartal/quintal sonorities, Whole-tone scales, Octatonic scales, and Odd and changing meters. Debussy’s fascination with the Church modes probably helped inform his approach to syntax since modally based music predated major-minor tonality and its associated harmonic functions. The characteristics of the pentatonic scale are: it contains no half steps (thus no leading tones), and it contains no more than two whole steps in succession. These two characteristics assure two others: a minor third occurs at two points, and no tritones are present. A structure inherent in the pentatonic scale is the quartal harmony, a stack of fourths. The quartal harmony can be restacked as a quintal harmony, a stack of fifths. Octatonic scale is an eight-tone scale having alternating half steps and whole steps, with several features that have appealed to composers.
