You are here

Lesson 6 - Standard non-diatonic chords

Many progressions which are primarily diatonic have one or two non-diatonic chords used to add harmonic interest. In this lesson we shall investigate the most widely used non-diatonic chords.

Subdominant minor
One of the strongest non-diatonic chords is the IVm or IVm6. It generally follows the IV and resolves back to the I or V chord. For example:

|GΔ	Am7	|Bm7	CΔ	|Cm6	D9	|G6		|
G:IΔ	IIm7	 IIIm7	IVΔ	 IVm6	V9	 I6

The above progression is diatonic in G major except for the Cm6. A C melodic minor (ascending) should be used in improvising over the Cm6.

I# diminished

The I#° chord is used to connect the I chord to the II chord with an ascending chromatic bass line as in:

|G	G#°	|Am		|

The diminished seventh is used when connecting IΔ to IIm7 as:

|GΔ	G#°7	|Am7		|

The diminished seventh is used to connect seventh chords (or other four, five or six note chords) rather than triads. Sometimes the diminished is also used to connect other scale degrees such as II and III or IV and V (G: Am7-A#°7-Bm7 or G: CΔ-C#°7-D7) but primarily it is found in a major key connecting I and II. Use a diminished scale for improvising. (C#dim7 takes a C# diminished scale). Often the I#° is used for only one beat or less as a passing chord and does not identify itself strongly enough to warrant a change of key center. If the I#° is only a beat or less in duration it can be ignored in terms of improvisation.

The subtonic chord

The subtonic chord bVII or bVIIΔ usually appears immediately before the dominant (V). This chord nearly always gets a whole measure or more and, consequently, reestablishes a new key center. I prefer to use the major scale of the root of the subtonic chord for improvising. For example:

|EbΔ		|AbΔ		|DbΔ		|Bb7		|
Eb:IΔ		IVΔ		Db:IΔ		Eb:V7

Some other jazz musicians prefer to think of the subtonic as a IV chord and use the major scale a fourth below the root of the subtonic:

|EbΔ		|AbΔ		|DbΔ		|Bb7		|
Eb:IΔ		IVΔ		Ab:IVΔ		Eb:V7

Either approach will work without any difficulties. Try both and decide on your preference or use both.

Alterations of the V chord

The V chord in a major key is a dominant seventh. Sometimes the V shows up with an altered fifth or ninth. The fifth or ninth is either flatted or sharped, creating the following possibilities for an altered dominant chord:

Possible altered dominant chords
V7(#5) V7(b5) V7(b9) V7(#9)
V7(#5/b9) V7(#5/#9) V7(b5/#9) V7(b5/b9)

This chord can be viewed as a borrowed V chord from the minor mode. (See lesson 9 on minor key harmonization for full explanation). Check the surrounding chords to see if they are diatonic to a minor key. If so you have modulated to a minor and a minor scale will be required. However, if the surrounding chords are diatonic to a major key, see the section in lesson 8 on altered dominant chords to determine solutions for improvisational problems.

The 7(#9) chord

The 7(#9) is often used in rock or jazz-rock as a I, IV, or V in a blues-type progression. It gives a harsh biting edge to the straight seventh chord rather than the smooth sound of a ninth chord. Use the pentatonic a minor third above the root of the I chord for a I7(#9), IV7(#9), and V7(#9). (Use the Eb pentatonic for C7(#9), F7(#9), and G7(#9)).

Chromatic mediants

A chromatic mediant is a major or minor chord a major or minor third above or below the key center. For example, the chromatic mediants of the key of C are E, Em, Eb, Ebm, A, Am, Ab, and Abm. However, the Am and Em are not technically chromatic mediants because they are diatonic chords in C. Any chromatic mediant can be a seventh chord (dominant seventh, major seventh, or minor seventh) or an extension of a seventh chord. Treat any chromatic mediant as you would any chord which stands alone. That is, treat a major seventh as a I chord, treat a minor seventh as a VI chord, and assume that a dominant seventh is a V chord. The same holds true for further extensions of the seventh chord (9th, 11th, 13th).

Chromatic mediants can occur as passing chords between diatonic sevenths. For example:

|C	Dm	|Ebm	Em	|

lf the chromatic mediant is held for less than two beats, you can treat it as a passing chord and ignore it in terms of improvisation. Usually, the chromatic mediant is held for one or two measures and then leads back into the original key. It usually leads back to the IV or V chord although it can lead to any diatonic chord. The principle quality of a chromatic mediant is that it stands alone in an otherwise diatonic progression. It comes from a diatonic chord and leads back to a diatonic chord. For example:

|CΔ		|FΔ		|EbΔ		|D7	G9	|
|GΔ		|Bbm7		|Am7	D13	|GΔ		|

Secondary dominants

A secondary dominant is a V chord (or V7, V9, V11, V13) which is not the V chord diatonic to the key. A7, B9, C13, E7sus, F#11, and G7 are all secondary dominants if used in progressions in the key of G. Every secondary dominant can be identified by the chord to which it leads. For example, in the key of G, a B7 would lead to an Em because E is a fifth below B. Therefore B7 is called V7 of VI (V7/VI). Em is the VI chord in G and B7 is the V7 which leads to VI. G7 would be V7/IV. E7sus is V7sus/II. F#11 is VII/III. The secondary dominant is a convenient chord for modulation to another key center. For example:

|FΔ		|Dm7		|Am7	D7	|GΔ		|
F:IΔ		 VIm7		 IIIm7	V7/II	
				G:IIm7	V7	 IΔ

The common chord Am7 is also instrumental in setting up a smooth use of the secondary dominant to establish the key center of G major. In improvisation, the first two chords would be in the key of F and require an F major scale. The last three chords require a G major scale. Secondary dominants of this sort should be familiar by this time for we have seen progressions which modulate in this manner in lessons 1 and 2.

It is not unusual to see secondary dominants "nested" in each other in a progressions of fifths. That is:

|E7		|A7	D7	|G7	C7	|F		|
F:V7/III	 V7/VI	V7/II	 V7/V	V7	 I

In improvisation you can treat each chord as a V chord or use pentatonic scales for each pair or chords.

Standard non-diatonic chords (in key of C major)


  1. Play the following progressions.
  2. Analyze each progression and determine key centers.
  3. Practice soloing ever these chord sequences by using a tape recorder to make a rhythm track or have a friend play the progression while you solo.

Copyright 2011 | Some Rights Reserved | Administrator: Henk Frans de Vries | Powered by Drupal | Theme by Danetsoft and Danang Probo Sayekti