Volume III · HarmonyStage 9 of 15
9
Harmony: sixth chords and the four scales of chords
The sixth diminished world: major 6 dim, minor 6 dim, 7th dim, 7b5 dim.
- 9.1 Sixth chords rule M7 = major 6, m7b5 = minor 6 Barry treated every minor seventh as a major sixth and every half-diminished chord as a minor sixth: Am7 is C6, Em7♭5 is Gm6. As sixth chords they belong to a sixth diminished scale, which tells you where to move them.
- 9.2 Two sixth chords for every major chord (6 on the 1, 6 on the 5) A major chord has two sixth chords: one on the tonic and one on the fifth (E♭6 and B♭6 for E♭). The first gives the sixth and root, the second the major seventh and ninth; play one and add a note of the other.
- 9.3 The major 6th diminished scale (a major scale with one more note) Barry’s sixth diminished scale is a major sixth chord plus the diminished chord sharing none of its notes: in C, C D E F G A♭ A B. He called it the real major scale; it holds the dominants of the key and relative minor.
- 9.4 Playing the scale of chords (block chords up and down the 6th dim scale) Played as chords, a sixth diminished scale becomes a scale of chords: sixth, diminished, sixth, diminished. Barry had players move whole voicings up and down it, in many textures, until a chord stopped being a fixed sound and became something you know how to move.
- 9.5 The minor 6th diminished scale and its diminished partner Flatten the third of the sixth diminished scale and you have the minor sixth diminished scale, C D E♭ F G A♭ A B: harmonic minor plus the sixth. Know at once each minor sixth’s diminished chord, and move between scales a minor third apart.
- 9.6 Half-diminished = minor with the sixth in the bass; major -> relative minor -> minor/6 A half-diminished chord is a minor chord with its sixth in the bass, as Monk put it. Know at once which major it comes from, and reach it by one movement: major, relative minor, then that minor with the sixth in the bass.
- 9.7 The important minor and the tritone’s minor (minor 6 dim over a dominant) A dominant has two minor sixth chords: the important minor on its fifth (G minor 6 for C7), and the tritone’s minor, a half step above its root (D♭ minor 6 for C7), whose scale works as an altered scale.
- 9.8 The 7th diminished and 7th flat 5 diminished scales The four scales of chords Besides the major and minor 6 diminished scales, Barry later taught two more scales of chords built the same way: the seventh diminished and the seven flat five diminished. Together they are the four scales of chords he said you should really know.
- 9.9 Chords from the diminished Raise or lower one or two notes Barry’s four chord types all come from a diminished chord with notes moved a half step: lower one note for a dominant 7th, raise one for a minor 6th, move two neighbouring notes for a major 6th, two opposite notes for a 7♭5.
- 9.10 The extended family and the musical universe One diminished chord gives not just four related dominants but four minor sixths, two sets of four major sixths and the 7♭5 chords: families a minor third apart. Barry’s clinic sets these families out after ‘The Musical Universe’ and uses them on V7 to Imaj7.