1. Harmony
The 12 notes of the octave encapsulate the entire musical system of traditional Jazz. Barry Harris analyzed everything within the limits. As with other forms of art, constraints allow creativity.
The major scale and the dominant scale are the two fundamental scales of the Barry Harris method. They use the same notes on a continuum, with each having a different sequence of half-step/whole-step intervals.
Here is a dominant scale (G dominant) moving to a major scale (C major). This is a V-I move in the key of C:
Note: the note interval C to F is a I-IV move in the key of C, and a V-I move in the key of F.
Jazz tunes generally follow a scale outline that moves between a V (= notes and chords in a dominant context) going back to a given I (= notes and chords in a major context). The V provides tension, and the I provides release. V is away, I is home. Tunes tend to move to additional tonal centers, but typically resolve back to the original tonal center by the end of the tune.
Other types of scales (e.g. pentatonic, blues scale, etc) should be interpreted in relation to a major scale or dominant scale context.
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The 2 whole tone scales (Barry Harris calls them mother and father) split the octave into two equal parts of 6 (e.g: mother: C, D, E, G♭, A♭, B♭. Father: D♭, E♭, F, G, A, B). Whole tone scales should be analysed within a dominant scale context (e.g, a whole tone scale with C in the root implies a C dominant scale context).
The whole tone scales “give birth” to the 3 fully diminished 7th chords. Each of the diminished chords has 2 notes from mother, and two from father. Barry Harris calls these 4 notes of a diminished chord: brothers and sisters (they are closely related).
A diminished chord consists of 4 notes, each separated by a minor 3rd interval (3 semitones). For example, a C diminished chord: C, E♭, G♭, A.
Due to the chord’s symmetrical structure, there are only 3 diminished chords. E.g: C° (C, E♭, G♭, A), D♭° (D♭, E, G, B♭), D° (D, F, A♭, B). The diminished chords that begin on the root of the other 9 notes, are just inversions of these 3.
Chords are just a set of intervals on a major or a dominant scale that are played all at once (or inversions of those notes).
Major 7th chords are on notes 1,3,5,7 of a major scale. Major 6th chords are on notes 1,3,5,6 of a major scale, minor 7th chords are an inversion of a major 6th, dominant chords are on notes 1,3,5,7 of dominant scale.
Note: diminished chords, ♯5 and ♭5 chords are not intervals on scales, so technically they are not chords. Minor chords (a major chord with a flat 3rd) will be discussed in the next chapters.
▪ Therefore, when playing chords, make use of their entire scale, for depth.
Notes and chords are always context dependent. They mean different things in different harmonic contexts, and belong to one tonal center at any given moment. To understand their harmonic context, identify the scale they are on, where they came from, and where they are going next.