Relationship to Other Chapters

This chapter connects fundamentally to Chapter III (Added Values), establishing the rhythmic-harmonic parallel that will recur throughout the treatise. It anticipates Chapter XVI (Modes of Limited Transpositions), where the perfect chord with added sixth and augmented fourth will be revealed as the characteristic sonority of the second mode. The chapter also references Chapter VIII (melodic contours) and previews Chapter XV (foreign notes and passing groups), demonstrating how added-note harmony integrates with melodic procedures. The aesthetic principle introduced here—enrichment through "foreign" elements that transform without destroying underlying identity—connects to the overarching theme of Chapter I, the "charm of impossibilities."