DIAGRAM XVI.—The seven of each harmony, with its scale—The pairs of the trinities and scales.

DIAGRAM XVII.—The roots of the minor chords—The difference between a major and a minor chord—The chords of the 12 minor keys follow.

DIAGRAM XVIII.—The 12 key-notes with their trinities and scales repeated, with the addition of the chords.

DIAGRAM XIX.—The minor gamut modulating in the meeting of fifths throughout 7 octaves.