Jean-Philippe Rameau · section 69 of 109

Chapter twenty-six

On Using the Seventh on All the Notes of a Key in Diatonic Progression

Only the tonic note must always appear with the perfect chord, whereas the seventh chord can be applied to all the others, with this distinction: in an ascending-fourth progression onto a perfect chord or seventh chord, all the notes must be regarded as dominants and may then bear the seventh chord. But in diatonic progression, the note bearing the seventh chord must be divisible into two beats or be sounded twice, which amounts to much the same thing, so that on its second beat it may bear the sixth chord suited to it according to the following note. The seventh must then always be prepared, except for the first, which may be unprepared according to the bass progression.

Example

A, B. I could have conformed the chords on these diatonic notes to the key declared by the following conclusion. But one may also continue in the preceding key, whose tonic at B takes, on its second beat, the chord appropriate to the following key.

The note at C should naturally bear the great-sixth chord, which may be heard after the seventh chord we give it. But instead of resolving that seventh onto the sixth of the same note, we resolve it onto the fifth of the immediately following note, because the small-sixth chord on that latter note and the great-sixth chord belonging to C are fundamentally the same chord. Hence, once a dissonance is heard, it should not be abandoned until it can be resolved. As the bass note on which it would naturally resolve does not always appear, one must see whether the following bass note could bear a chord made up of the same sounds as the chord in which the dissonance should have resolved. This will now be explained.