This chapter explores the sources and evolution of the new musical language that lead to the symbolist ideal and corresponding musical processes. The latter is based on transformation of traditional diatonic pitch constructions, symmetrical, and cyclic-interval properties of the dominant-ninth chord and other traditional harmonic constructions, as developed by Russian nationalist, French impressionist, and Hungarian composers. The interaction of pentatonic, diatonic, whole-tone, and octatonic sets by means of common suhcollections or cells is essential to the new twelve-tone language based on the concept of the interval cycle.