GENERALIZATION OF HARMONIC PROGRESSION
All harmonic progressions, regardless of style, adhere to the following guidelines:
- roots change between adjacent chords;
- relative strength of chord roots is varied by inversion and voicing, with chords that possess strong roots acting as harmonic goals or pillars;
- relative tension between chords ebbs and flows through changes in dissonance and density;
- functional categories of chords are created through maximal similarity (i.e., common tones);
- voice-leading governs the coherence of the musical surface.