Jean-Philippe Rameau · section 13 of 109

Chapter ten

Observations on the Different Ratios That May Be Given to the Same Chord

Observe that we have made the ratios of the chords conform to those of the intervals between the notes composing each chord. Since the same interval can be given by two different ratios, most of the preceding chords can undoubtedly share this difference when taken on notes other than those we have used. See the chromatic system above, Chapter V, p. 28. These different ratios, however, will not give us new chords. The fifth between 27 and 40 is the same as that between 2 and 3, and similarly for the others. The difference between these two ratios, imperceptible to the ear, arises only from the different disposition of the whole tones and semitones composing them. The note names should be immaterial here; we have used them only to make the whole more fully intelligible.