• # The Secret Link Between Dominant 7 [b9] Chords

The dominant seventh chord is undoubtedly one of the best things that ever happened to chord progressions.

“In fact, is it possible to create as strong of a pull or resolution to a chord without the introduction of the dominant seventh?

The answer is a resounding: No.

The dominant seventh chord family has several varieties (aka – “extended dominant chords”) that can be created using extensions (or compound intervals). We covered a few of them in this previous post.

In today’s lesson, we’ll be focusing on the dominant 7 [b9], which is one of the extended dominant chord varieties, dissecting it to reveal the secret link dominant 7 [b9] chords share.

## The “Dominant Seventh Flat Nine” Chord

Below is the dominant 7 [b9] chord:

Before going any further, let’s go back to the regular dominant seventh chord.

After all, the base chord is a dominant seventh, even before you consider the “flat nine.”

### Dominant Seventh – Explored

Remember that the dominant seventh is the chord of the fifth degree.

Using the major scale of F:

…we can form a dominant seventh chord on the fifth scale tone (C) by stacking thirds.

C:

…followed by E:

…G:

…followed by Bb:

Altogether, we have the Cdom7 chord:

*Shortcut: When creating chords from a major scale, simply start on a desired tone and select every other note until you have three or four notes pressed down. Three notes will create a triad, four notes will create a seventh chord. That’s all we did here (aka – “pick n skip“).

Someone’s probably asking at this point, “That’s the dominant seventh, what about the flat nine?”

### “…flat nine”

The ninth degree from this C:

…is this D:

…therefore a flat nine suggests the lowering of D (remember, the “flat” tire always lowers the car):

…to Db:

…and will produce the b9.

If we go ahead and add Db (the b9) to our C dom 7 chord, we’ll have a dominant seventh chord with a flat nine (aka – “dominant 7[b9]”):

The name, dominant 7 [b9], at this point, should bring this picture:

…to mind.

This is because you can clearly see the dominant seventh:

…and the flat nine:

…all in one chord (dominant 7[b9]).

## Dissection of the Dominant 7 [b9]

Let’s get into the dissection of this chord by answering one simple question:

“If the root of a dominant 7 [b9] chord is transposed an octave lower:

…what chord quality can best describe its upper part?

If the dominant 7[b9] chord is played without its root (rootless voicing):

…the chord quality that best describes the right hand part is the E diminished seventh chord.

There is a system of chord writing (aka – “chord notation”) known as the slash chord.

In this system of writing, C dominant 7[b9] is written as E diminished 7th / C. The slash chord name of the dominant 7[b9] makes it easier for us to see it in terms of right hand / bass.

“E diminished7 / C” simply means “playing an E diminished 7th chord over C on the bass”.

Having discovered the upper part and identified it as the diminished 7th chord, let’s dwell a little more on it before finding the secret link.

## Diminished 7th Chord

The diminished 7th chord shows signs of symmetry.

Symmetrical chords are chords that have equal intervals between chord tones.

The E diminished 7th chord:

…can be broken down into a string of minor third intervals.

E to G:

…that’s a minor third.

G to Bb:

…that’s another one.

Bb to Db:

…that, of course is a minor third.

One striking feature about symmetrical chords when played in all keys is that they are related by inversion.

Inverting E diminished 7th:

…will produce:

…which is essentially G diminished 7th, but spelled differently (same sound though). Here’s the correct spelling:

Two other inversions will produce chords that sound like Bb and Db diminished 7th chords, respectively. I only say “sound like” because of their spelling. However, informally they are Bb and Db diminished 7th chords!

Here’s what I mean:

Bb diminished 7th:

…even though it is spelled as Bb-Db-Fb-Abb, the second inversion of E diminished is enharmonic (spelled differently but makes the same sound).

If we compare the tones side by side:

 Bb diminished seventh E diminished seventh(2nd inversion) Bb Bb Db Db Fb E Abb G

…we can see that the clear difference is the spelling of Fb as E and Abb as G.

Db diminished 7th:

…even though its proper speling is Db-Fb-Abb-Cbb, the third inversion of E diminished is enharmonic.

If we compare the chord tones of both chords side by side:

 Db diminished seventh E diminished seventh(3rd inversion) Db Db Fb E Abb G Cbb Bb

…we can see that the clear difference is the spelling of Abb as G and Cbb as Bb.

Attention: There are situations where you can ignore spelling guidelines. This lesson is one of them. The goal of this post is to show you a secret link. Sometimes, it is necessary to step out of orthodox methods to see the links and connections between notes, scales, chords, and progressions.

From this point on, we’ll use E diminished seventh to represent similar diminished seventh chords, ignoring wrong spellings (for my theorists out there).

Come to think of it, which of these is easier?

Db diminished spelling vs E diminished seventh

Use of Fb vs Use of E

Use of Abb vs Use of G

Use of Cbb vs Use of Bb

So you clearly see the reason we’ll have to sacrifice the strict spelling guideline… so you can see the secret link!

## “Show Me That Secret Link…!”

Now that we’ve explored the dominant [7b9] chord inside out, let me show you the secret link.

Below is E diminished 7th / C (aka – “C dominant 7 [b9]”):

Movement of the bass note in three half steps (aka – “sesquitone progression“), will show us the secret link.

Pay close attention here…

Moving our C bass note up by three half steps will take us to Eb:

Moving the Eb bass note (in turn) up by three half steps will take us to Gb:

Moving the Gb bass note by another three half steps in the ascending direction will take us to A:

We’re not done yet…

If we this A bass note up by three half steps, this will take us back to C:

…and that’s another C dominant 7[9].

### “So, what were we doing all along?”

We took the bass notes up by three half steps each.

This bass movement produced three other bass notes – Eb, Gb and A.

If we stack them above C:

…this will produce a C diminished seventh chord (a topic for another day).

E diminished 7th:

…can be played over any of these bass notes:

This will link four dominant 7[b9] chords:

C dominant 7[b9]:

Eb dominant 7[b9]:

Gb dominant 7[b9]:

A dominant 7[b9]:

## Final Words

We can link up dominant 7[b9] chords that are related to each other by moving bass notes in a diminished seventh chord outline.

For example, if given D dominant 7[b9]:

…feel free to move the bass notes in three half steps (in a diminished seventh outline).

If you’re familiar with diminished seventh chords, instead of counting three half steps in each case, you can visualize the D diminished seventh chord:

…and using each of the bass notes above, you can play the following dominant 7 [b9] chords:

D dominant 7 [b9]:

F dominant 7 [b9]:

Ab dominant 7 [b9]:

Cb dominant 7 [b9] (aka – “B dominant 7[b9]”):

A “4 for 1” special. Without moving a thing on your right hand, you’ve now learned how to produce 4 different chords.

I hope someone will find this useful.

I’ll see you next time.

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#### Chuku Onyemachi

Head of Education at HearandPlay Music Group
Onyemachi "Onye" Chuku (aka - "Dr. Pokey") is a Nigerian musicologist, pianist, and author. Inspired by his role model (Jermaine Griggs) who has become his mentor, what he started off as teaching musicians in his Aba-Nigeria neighborhood in April 2005 eventually morphed into an international career that has helped hundreds of thousands of musicians all around the world. Onye lives in Dubai and is currently the Head of Education at HearandPlay Music Group and the music consultant of the Gospel Music Training Center, all in California, USA.

#### Latest posts by Chuku Onyemachi (see all)

1 zino

great , eye opning

2 paul

hmmm…chord scientist. thanks