Harmonic Analysis - Scale Selection

Once a harmonic analysis has been completed then scale selections can be made. These scale selections can be either vertical and horizontal choices.


Vertical Scale Choices


This is a scale per chord approach. When a new chord is encountered the scale is changed based on the chart below. This is a basic scale selection approach. Additional scales can be played against these chords using the same principles that are used with chord substitution (see the Substitution Principles chapter).

Horizontal Scale Choices


Scale choices can be made based on the overall tonality of a progression or portions of a progression using horizontal scale choices. The scale will stay in effect until the analysis requires a different scale.


Here are the scale choices applied to the six harmonic principles.

Full Diatonic Chords


Full Diatonic Major


• Use the Major scale of the I chord


Full Diatonic Minor


• Use the Natural Minor scale of the I chord on I and III chords
• Use the Harmonic Minor scale of the I chord on V and VII chords
• Use the Natural Minor scale or Harmonic Minor scale of the I chord
 on II, IV, and VI chords


Sample Scale Choices for II V of a II V I


• Harmonic Minor of the I chord traditional sound

• Locrian of the II for a more contemporary sound


Partial Diatonic


Use the vertical scale per chord approach.


• For Seventh chords resolving up a perfect fourth (or down a perfect fifth) to a major chord type use a Mixolydian scale.

• For Seventh chords resolving up a perfect fourth (or down a perfect fifth) to a minor chord type use a Mixolydian -2 -6 scale.


Internal Modulation


Use a Full Diatonic or Partial Diatonic solution.


Unresolved


Use a Full Diatonic or Partial Diatonic solution.


Cycle


Use a Full Diatonic or Partial Diatonic solution.


Chromatic


Use a Full Diatonic or Partial Diatonic solution.


• For Seventh chords functioning as a bII7, bIII7, bV7, bVI7 or bVII7 use a Mixolydian +4 scale.


Alternate Scale Choices


Alternate scale choice should be based on the same principles as chord substitution.


The Lydian Scale Uses vs. Ionian Scale


If a major chord is not in a full or partial diatonic progression then the Lydian scale is the better vertical scale choice.