"Our music has sprung from the patient, incessant, and progressive penetration into the law of resonance, that is to say, from the successive exploitation of the octave, the fifth and the fourth (ninth to twelfth century), the third (thirteenth to sixteenth century), the seventh (seventeenth and eighteenth century), the major ninth, the augmented fifth, and the perfect eleventh (nineteenth and twentieth centuries) . . . . this evolution . . . . constitutes, at the same time, the only true justification of the musical art."