Dominant Chord - Jazz Harmony

Dominant Chord

Part 2: Slightly Altered – Mixolydian b13

The dominant chord provides movement in tonal music: its tendency to resolve (aka “to go somewhere else”) is very strong. It has an even stronger harmonic pull when the seventh is added on top of it.

The dominant seventh is used most of the time in jazz music. If you look at sheet music or in fakebooks, dominant seventh chords have “just a number” so to speak : they’re identified with “7” (or “7th”), “9”, “7(b9)”, “13” or “13(b9)” and “dom7” and so on.

In this series we will look into the most common colors for the dominant chord. I like to approach them by their respective sound, starting with the most consonant and moving towards more alterations of the basic sound

Please note: All examples will use a G dominant chord throughout this article series. I chose this key because it resolves back to a C (which the basic key of reference … or “the people’s key” as a good friend likes to call it!) Good old C major.

Jump to a page:

Dominant Chords Introduction
Dominants Part 1: The Basic Sound – Mixolydian
Dominants Part 2: Mixolydian with a flat 13th
Dominants Part 3: Mixolydian with a sharp 11th
Dominants Part 4: Mixolydian with a flat 13th and a flat 9th
Dominants Part 5: Super Locrian (aka altered scale aka Dim Whole-Tone)

Mixo b13th what?!

This spicier dominant color is slightly altered when compared to the straight-ahead mixo: the 6th degree (aka 13th) is flat. As we already know, the dominant is usually built on the fifth degree of a scale. Here, we’re using the melodic minor scale as our starting point.

C melodic minor scale contains the same notes as G mixolydian b13 scale:

Dominant Chord

In brief: By playing the C melodic minor (C D Eb F G A B) but starting on G (G A B C D Eb F) …we get that infamous G mixolydian b13 sound! That explains why some call this “melodic minor of destination” or MMD. And, YES, it’s that simple!

A Closer Look

If we go in a bit deeper and take the mixolydian b6 scale apart and build it back we’ll find…

The scales degrees 1 2 3 4 5 b6 b7

Dominant Chord

A compared to a G major scale, the E is flat and the F natural… thus we use “flat 7” and “flat 6” to qualify those tones.

Vertical chord tones 1 3 5 b7 9 11 b13 

Dominant Chord

Notice how Eb can be called a b6 or a b13… it’s the same thing!

Learning Mixolydian b13

Use practice suggestions on the introduction page to learn the basic mixolydian b13 dominant chord sound. And here’s some more stuff to think about…

On the Guitar, in Positions :

Take any of the seven positions of melodic minor and start on the fifth degree; it’s that simple again! For example, G mixolydian b13 comes from C melodic minor… so here’s G mixolydian b13 based (with minor adjustments) on the “52” position of C melodic minor scale:

Dominant Chord

Notice I didn’t use a regular “1 3 5 b7” arp… Here I used an arpeggio that outlines the characteristic notes of the chord: 1, 3, b6 and b7. The b6th is unique to that chord… not the 5th. Choosing “chord defining” notes is a great way of outlining different chord types.

You can, of course, also practice arpeggios that go up to the 9th, the 11th and the b13th etc. and some inversions (and/or all of the above mixed-up!) And all of that in many positions.

On the Guitar, Diagonally:

This is much more subjective, it depends on the player and situation. Here’s how I would play that dominant chord mixolydian b13 scale and arpeggio. On two octaves diagonally:

Dominant Chord

And on three octaves diagonally (notice the finger slides):

Dominant Chord

The fingerings for diagonal playing are not “set in stone” once again : a few useful sets of fingerings exist. Again, you have to find your own way of doing that (and practice arpeggios that go up to the 9th and above…)

Applying Mixolydian b13

In jazz music, we hear this sound primarily when a dominant chord is resolving to a tonic minor chord. For example : G7(b13) to Cm6. That b13 (or b6) sound is often misspelled “#5” on lead sheets. Remember that the #5 and b6 are enharmonic equivalents (Eb = D#, the same exact note) but they have different functions:

On a dominant b13, there IS a 5th (and it’s natural)

…on a dominant #5, there IS NO natural 5th.

This was either by mistake (or ignorance) but it is widespread in fakebooks. Whenever you see a dom7(#5), ask yourself if the real intent of the composer was that mixolydian b13 scale. Sometimes, it easy to find out, sometimes not…

So, how to apply?

While keeping the practice suggestions from the introductory page, I would suggest that you try the same usual mixolydian stuff you’re used to play and emphasis the only different note: the b13! For instance, improvise on major or minor II-V-I’s using the right scales, arpeggios or guide-tone lines all the while making that b13 (b6) note really stand out on the V chord.

Have Fun!

Jump to a page:

Dominant Chords Introduction
Dominants Part 1: The Basic Sound – Mixolydian
Dominants Part 2: Mixolydian with a flat 13th
Dominants Part 3: Mixolydian with a sharp 11th
Dominants Part 4: Mixolydian with a flat 13th and a flat 9th
Dominants Part 5: Super Locrian (aka altered scale aka Dim Whole-Tone)

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