Chord scale system



Audio: chord scale system (0:16)

Chord scale system
Figure: chord scale system

chord scale system plays chords constructed from four different scales on a clean jazz guitar with no effects. The chord scale system figure shows the score in tablature. The chords are constructed from the following scales:

  • Bar 1: F mixolydian.
  • Bar 2: C jazz minor.
  • Bar 3: D phrygian.
  • Bar 4: Eb whole tone.
  • Bar 5: Ab acoustic.
  • Bar 6: B whole half diminished.
  • Bar 7: G whole tone.
  • Bar 8: C jazz minor.

The chord scale system is based on the unity of chord and scale.

A chord and a scale are a unity in the chord scale system. A single chord can be constructed from any scale, and a scale can be used to construct any number of chords.

The chord scale system is a logical extension of modal jazz. It incorporates the seven modes used in modal jazz. In addition, it extends the concept of mode to cover any scale. This notion of mode applies, in particular, to the jazz minor scale. The jazz minor scale is an invented scale, it is the ascending version of the melodic minor scale. The scale also has seven modes, depending on the starting note. In this way of thinking, every scale has modes.

21 scales are commonly used in the chord scale system:

  • 7 scales based on the modes. These are the ionian mode, the major scale, and the other six related modes.
  • 7 scales based on the ascending version of the melodic minor scale:
    1. The jazz minor scale based on the first degree of the scale.
    2. The phrygian natural 6 scale based on the second degree.
    3. The lydian augmented scale based on the third degree.
    4. The acoustic scale based on the fourth degree.
    5. The aeolian dominant scale based on the fifth degree.
    6. The half diminished scale based on the sixth degree.
    7. The altered scale based on the seventh degree.
  • 4 bebop scales.
  • 2 diminished scales. The diminished scale is an octatonic scale, a scale with eight notes. The eight notes form a series of semitones and whole tones:
    1. The half whole diminished scale starts with a semitone above the tonic.
    2. The whole half diminished scale starts with a whole tone above the tonic.
  • 1 whole tone scale with 6 notes.

All these scales can be derived from the major and the chromatic scales. The major scale is used to derive the 7 modes. A major scale with a flattened third forms the ascending melodic minor scale, and this is used to derive the 7 jazz minor modes. A major scale with an extra chromatic note inserted between two of the notes gets you most of the bebop scales. The chromatic scale is used to derive the rest of the scales. A series of semitones produces the chromatic scale, a series of whole tones produces the whole tone scale, an alternating series of semitones and whole tones produces the half-whole diminished scale, and an alternating series of whole tones and semitones produces the whole-half diminished scale.

Writing chord scale jazz can start with a scale or with a chord. Starting with a scale is a matter of choosing a scale then choosing a mode from that scale. Starting with a chord is perfectly feasible too as there will usually be at least one mode that will fit the chord. chord scale system is based on the chord progression, IV-i-ii-III+-bVI-viio-V-i, in the key of C jazz minor. The root of each chord is notated in the score.

One interesting consequence of the chord scale system is that there is pretty much no such thing as a wrong note. A note can always be made to fit one scale or another.