Harmonizing the Harmonic Minor Scale I: Triads

The process of harmonizing a scale involves building chords on each degree (note) of the scale, using only notes from that scale.

This post will:

Take us through the process of harmonizing the harmonic minor scale with triads.
Analyze the chords that result, along with the Roman numerals assigned to each chord.
Show the relationship between the chords in a harmonized harmonic minor scale and the scale itself.
Provide instruction on how that relationship relates to soloing on a guitar.

Harmonize a Harmonic Minor Scale: Alter a Harmonized Natural Minor Scale

The harmonic minor scale is identical to the natural minor scale but with a raised seventh scale degree.

So instead of harmonizing the harmonic minor scale from scratch, we will use the harmonized natural minor scale as our starting point, and then alter the seventh scale degree in each of the chords that contain that note.

Harmonized A Natural Minor Scale

A harmonized A natural minor scale is shown in fig.1.

Fig.1

Harmonized A Harmonic Minor Scale

The only difference between an A natural minor scale and an A harmonic minor scale is the raised seventh scale degree (G#) in the harmonic minor scale (fig.2).

Fig.2

So to construct a harmonized A harmonic minor scale from a harmonized A minor scale, we need to change all of the G’s in the harmonized minor scale to G#’s in the harmonized harmonic minor scale in the chords that contain that note.

A harmonized A harmonic minor scale is shown in fig.3.

Fig.3

Diatonic Chords: Triads

The raised seventh scale degree (G#) in an A harmonic minor scale is included in three of the chords in the harmonized scale — the bIII+, V and vii° chords.

Consequently, the qualities of those chords change from what they were in a harmonized natural minor scale, where the flatted seventh scale degree was G:

The bIII+ chord is augmented.
The V chord is major.
The vii° chord is diminished (and the root note of the chord is a half-step higher than it was in a harmonized natural minor scale).

The other four chords remain unchanged.

Roman Numerals

Every harmonic minor scale has seven triads that are diatonic to it, one chord for each scale degree.

And each of the seven diatonic chords is assigned a Roman numeral, which reflects the chord’s position within the key, relative to the tonal center (the first note or chord).

The Roman numerals representing the triads diatonic to an A harmonic minor scale are shown in fig.5.

Fig.5

Sequence of Chords

Every harmonized harmonic minor scale has the same sequence of chords. As the sequence of chord qualities is the same in every key, the sequence of Roman numerals is also identical.

In any given harmonic minor scale:

The i and iv chords are minor.
The V and bVI chords are major.
The ii° and vii° chords are diminished.
The bIII+ chord is augmented.

All 12 Harmonized Harmonic Minor Scales

All 12 harmonized harmonic minor scales are shown in fig.7.

Fig.7

Soloing Application

In general, you can use a harmonic minor scale to solo over any of the chords that are diatonic to it because the notes generally won’t clash with the chords.

For more specific soloing applications for the harmonic minor scale, see the post entitled Modes of the Harmonic Minor Scale III.