Diatonic Standing Wave Model

According to harmonic interference theory, the 7-tone diatonic scale of common practice music can be represented as a frequency doubling (first harmonic) of a 12-tone octave standing wave. Both are centered on the ninth harmonic partial (e.g., D in the key of C), which acts as a harmonic center for the oscillating spring effect known as the Tritone Function.

Pulling and pushing between the diatonic tritone (e.g., B,F) and major third (e.g., C,E) in diatonic scales, the Tritone Function is the central physical and physiological engine behind melodic and chordal progression; consonance and dissonance; and tension and resolution. It is recognized naturally by the human auditory system - not taught through cultural conditioning as many cognitive scientists believe. This recognition of standing wave oscillation and energy flow/ exchange transcends any scale, tuning, or temperament, though the equal octave division by twelve offers the greatest contrast for recognition (not concordance) of standing wave oscillation.