5. Diatonic Chords
Diatonic chords are chords whose notes are all on a single scale, and there is a diatonic chord on each scale degree. They orient you within a tune and provide improvisation possibilities.
The pattern of diatonic major chords: M7, m7, m7, M7, V, m7, ♭5.
The pattern of diatonic dominant chords: V, m7, ♭5, M7, m7, m7, M7.
Now we can combine the two (as chords diatonic to the major and chords diatonic to the dominant are on a continuum) and interpret diatonic chords in a way that flows with the Barry Harris method:
… M6 m6/7 m7 M6 V m7 ♭5 …
M6
(M6, as M7 has borrowed note).
m6/7
(m6 or m7, both are diatonic).
m7
(m7 = inversion of a M6).
M6
(M6, as M7 has borrowed note).
V
(Dominant chord).
m7
(m7 = inversion of M6 on I).
♭5
(m7♭5 = an inversion of a m6)
Internalizing the diatonic sequence of chords is important for orientation in tunes. A diatonic chord provides information about the position in the harmonic pattern.
▪ Diatonic chords provide a range of improvisation opportunities, and are widely used in traditional Jazz.
When improvising with diatonic chords be sure to resolve back to the harmonic pattern of the tune.
Note: The diatonic chords above are not the only chords that can be played in the context of a scale. The additional options (e.g: secondary dominants, minor ii chords that lead to them, family chords etc.) require deeper analysis for proper harmonic use. More on this to come.