How Does That Work? Altered Extensions – You’ll Hear It

Adam Maness flys solo on this episode of “You’ll Hear It” to tackle how altered extensions work.

See more of Adam’s “How Does That Work?” series:

I’m Adam Maness and you’re listening to the “You’ll Hear It” podcast –  daily jazz advice coming at you. Coming at you solo today cause Peters in Europe and I’m here in St. Louis. I think he’s gonna be checking in a little bit next week with his own versions, on the road, of the “You’ll Hear It” podcast.

But this week I’m going to take the helm at the piano with some solo versions, and I want to do something a little bit different. I want to do a brief series of basic jazz theory called “How Does That Work?”

Today is our first edition and this will be all about altered dominant chords. How does that work?

I want to tell you. So, altered dominant chord might be something that – a term that – you’ve heard before. Maybe you know all about them. If so you can press next, but if you want a refresher on them and how to use them and how to create them you’re at the right place.

Let’s start with what is a dominant chord? So a dominant chord is a seventh chord. So, if you’re in the key of C you would see C7, right?

…it’s that sound.

Now we call these dominant chords because they usually lead to the tonic, right? This (the dominant chord) is kind of the second strongest chord in any given key, and they resolve just beautifully to the one of a key, whether that’s major or minor?

So a dominant seventh chord is built off of the root of the fifth degree of the Ionian scale. For instance, in the major key, so if we’re in the key of F, it’s C-E-G and then Bb, right? because we’re in the key of F.

Now in jazz, we like to throw in extensions on most of our chords. So we’re not satisfied with this… … We like to add in the ninth, and then we like to go even further with the eleventh – except on the dominant chord we like to sharp it.

This is our first altered dominant chord because F# is not in the key of F major, obviously, it’s not in the C-mixolydian scale , right? Which is what we’ve built this on so far, we’ve built it on the mixolydian scale, right? And so when we add the eleventh – the #11th – now we’re out of that sound, and it’s an altered dominant, because it’s altered from its original scale.

We also like to add the 13. So here’s the natural-13. Now often you hear this very voicing C-E-Bb, we leave out the 5th completely, 9: D, #11: F#,  and 13: A.

Alright? This is called a C7#11 or C13#11 if you want to get very, very specific. But oftentimes you’ll see C7#11 and it’s perfectly great to play this right?

So, within any altered dominant chord basically any of the extensions. the 9th, the 11th, or the 13th, can be altered. The 9th can go either way sharp or flat – so here’s what a C7#9 sounds like.

You’ve heard that before, right?

This is a really interesting chord because you have both the E and the Eb, right, the major third and the minor third, only it’s the #9.

Now you can’t have an Eb in this C7 and call it a #9 unless you have an E-natural somewhere in the chord. If not, it’s just a minor chord, because that is just the (minor) third, right? So, you have to have – for it to be a C7#9 – you have to have the E-natural in there somewhere, so that it’s a dominant chord.

And you’ve heard this all… … Jimi Hendrix. But especially in jazz, you know Duke Ellington loved these chords.

So that’s the #9, now you can also have the b9, right, so C-E-Bb and Db.

Now we can add the 13th to this, and the #11, and this is a C13#11b9.

Now, you’re saying, “Adam why would you ever use that?”

Well this is built off of the half-whole diminished scale which is a great scale to use going to your one (chord).

So, this C7b9#11 with the natural-13, C-E-Bb-Db-F#-A, is just a really great altered dominant chord and scale off that half-whole – half-step, whole-step, starting on C – going to F.

Right? Sounds great, you’ve heard that sound a million times, very common C7b9#11 with the natural-13. And it sounds more complicated than it is. Really it’s just those are the altered extensions, right, the 9th, the 3rd, the 11th, and the 13th. The 13th is the only one that’s natural, the 11th is sharp, and the ninth is flat.

Okay, another altered dominant we can do is the #9b13, right?

So, pianists often think of this is like an Ab triad over C7. We have C-E-Bb, and then like you put an Ab triad over there it sounds just great.

Now, this is based on the altered scale… …which is based off the 7th degree of a Db melodic-minor (scale.) Easy way to think of it is the melodic-minor from a half-step above your root; your C, so Db melodic-minor starting on C.

C-Db-Eb-E (natural)-Gb-Ab-Bb-C

Right? So this chord is called the #9b13, but it’s based off of the altered scale.

And it’s close to our last, our final, altered dominant chord – and really the most kind of crunchy one which is the C7 altered.

Now the altered is all of the altered extensions. So we have, and it’s based off, again off, of the altered scale. So we have b9, #9, #11, b13, all those in any combination.

So, when you see C7 alt. that’s what that means. It means that all of those upper extensions: the 9th, the 11th, and the 13th are altered. The 9th is both flatted and sharped, the 11th is sharp, and the 13 is flat.

By the way, the ninth is the only one that can be both flatted and sharp. The 11th is almost always sharp and the 13th is almost always flat. If the 13th was sharp it’d just be the dominant 7th. So when I’m (playing) an altered dominant chord it wouldn’t make sense to have two Bb’s in there, since you already have it, it’s represented.

So, that’s altered dominants, How do they work?

Hope you enjoyed it go to the You’ll Hear It blog to check out all of our free content, and go to to check out all of our full courses. We just released, Friday, our new Jazz Piano Technique course where Peter Martin and I guide you through…

…that’s the bell for the release of that course… we guide you through four weeks of guided practice sessions. We practice with you to get your chops up. It’s only been three days but I’m sure it’s massively popular already. So go check that out! Go to and until tomorrow, you’ll hear it.

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