Advanced Chord Scales, Part 2

By this time, you should be familiar with the basic method for choosing chord scales. This lesson goes a little deeper into the topic, and provides some specific chord scales for each chord by function. This is only an introduction, and many more possibilities exist.

Chord Scales for Diatonic Major and Minor Chords

These chord scales are just the basic modes, except of course we’ll make note now of what function each scale tone has, and we’ll especially indicate avoid notes, or tones that are not a valid tension.

As for the minor key, whether the whole progression is in the minor key or just one chord is “borrowed“ from it, all chords have the same chord scale with the exception of the V⁷, which will be explored later in this lesson.

I^maj7or ♭III^maj7 – Ionian Chord Scale

The fourth note is generally avoided.

II^-7or IV^-7 – Dorian Chord Scale

The ♮13 is what characterizes the Dorian sound. However, it would normally be avoided as it would result in a tritone with the minor third.

III^-7or V^-7 – Phrygian Chord Scale

Only tension 11 is used here.

IV^maj7or ♭VI^maj7 – Lydian Chord Scale

Have at it. Every note in the scale is available.

V⁷or ♭VII⁷ – Mixolydian Chord Scale

Scale degree four is avoided, though it is the tonic of the key for this chord scale on a chord with this function. The Mixolydian chord scale is also useful for many other chord functions, and is generally an option for any plain dominant 7^th chord.

VI^-7or I^-7 – Aeolian Chord Scale

Scale degree ♭13 is avoided.

VII^-7♭5, II^-7♭5 – Locrian Chord Scale

9 is not available, but ♭13 is.

Harmonic Minor V⁷

The minor key introduces the possibility of a V⁷, which normally gets a Phrygian dominant scale, also called a mixolydian ♭9 ♭13. This is just a fancy term for the 5^th mode of the harmonic minor scale.

Chord Scales for Secondary Dominant chords

As a general rule of thumb, Phrygian dominant is also a good starting point for secondary dominant chords resolving to a minor chord, such as V/II. For secondary dominant chords resolving to a major chord, Mixolydian chord-scale will often suffice.

V/II, V/III, V/VI – Phrygian Dominant Chord Scale

The dominant chord has an open structure which is very tolerant of many different kinds of tensionA note which, though not an essential part of a chord’s structure, can be added to the chord for additional coloring.s.

V/IV, V/V – (Option 1) Mixolydian Chord Scale, Lydian ♭7

The Mixolydian scale best represents the case of what is theoretically happening. For instance, a V/V is theoretically a tonicizationA method of composition which, usually temporarily, gives rise to the feeling that the tonal center has changed. For instance, the VI^min can be tonicized by preceding it with the V/VI secondary dominant chord., of the major key of the V chord. Therefore, the chord-scale for the V⁷ of that key is the most natural. However, a secondary dominant is already introducing some notes to the key that are a little bit weird. How about playing a whole-tone or Lydian ♭7 scale instead? Who can judge you if that’s what you’re into?

V/IV, V/V – (Option 2) Lydian ♭7 or Whole Tone

See below, “Substitute Dominant Chords” for these scales.

Chord Scales for Diminished Chords

Diminished chords are constructed from a symmetrical structure. There are only a total of two diminished scales and four diminished chords.

There are two diminished scales: whole-half and half-whole. The one to choose depends on the chord to follow. If the diminished chord is moving up a half step, the scale should be half-whole, so that the chord scale contains the root of the chord that is to follow. If the diminished chord moves down by half step, the scale will be whole-half.

Due to the exceptional nature of the diminished structure, we’ve declined to label the non-chord-tones for whatever tension they might be, but a case can certainly be made for it.

Whole-half diminished chord scale

Whole-half diminished chord scale

Chord Scales for Substitute Dominant Chords

Substitute dominant chords often like to be played with Lydian ♭7 or with the whole tone scale. That’s because their notes all fall within a row of whole-tones.

Lydian ♭7 is not as easy to play as the whole tone scale, but it does sound more “in”.

Whole Tone – another plus of the whole tone scale is it’s quite easy to play on guitar.

As the creator of Hub Guitar, Grey has compiled hundreds of guitar lessons, written several books, and filmed hundreds of video lessons. He teaches private lessons in his Boston studio, as well as via video chat through TakeLessons.