1. Harmony
The 12 notes of the chromatic scale encapsulate the entire musical system of traditional Jazz. Barry Harris analyzed everything within the limits of the octave. 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. Note that they use the same notes, on a continuum. Bassline voicings provide structure, clarity of context (i.e the position within tune), and allow for clear resolution.
The circle of 4ths and 5ths: A perfect 4th is ascending (I to IV), and a perfect 5th is descending (V to I). Example: C to F is I to IV in the key of C, but it is V to I in the key of F.
Other types of scales (e.g. pentatonic, blues scale, etc) should be interpreted in relation to a major scale or dominant scale context.
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.
The 2 whole tone scales (that Barry Harris calls mother and father) split the chromatic scale into two equal parts of 6 (e.g: mother: C, D, E, F♯, A♭, B♭. Father: C♯, 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).
Whole tone scales “give birth” to the 3 fully diminished 7th chords (these are the children, brothers and sisters who are harmonically related). Fully diminished 7th chords are central portals in the Barry Harris method. Note that each fully diminished 7th chord (which I will call diminishd chords from now on) has 2 notes from mother, and two from father.
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 three unique diminished chords: C° (C, E♭, G♭, A), C♯° (C♯, E, G, B♭), D° (D, F, A♭, B). The next chapter (“Family”) covers the diminished chords and their deep logic.
Chords are intervals on a major or a dominant scale. 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: fully diminished 7th chords, ♯5 and ♭5 chords are not intervals on scales, so technically they are not chords. Minor chords (a major chord with a flattend 3rd) will be discussed in the next chapters separately.
▪ 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 in the tune. To understand their harmonic function, identify the scale they are on, where they came from, and where they are going next.
Many Great American Songbook tunes follow an AABA form. The first two A sections are the core of the tune with slight variation. The B is the bridge, where the tune departs into a different melodic path. The final A is for resolution.