Diminished Scale Theory

Hi Hayden, in the handout titled Diminished Scale Patterns, what is the basis of the Diminished Scale ? I am curious about the accidentals. Sorry for what may seem like a simplistic question.

Cheers, Natasha

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Hi Natasha,

Fantastic question.

Diminished is a fascinating subject… one that I have recently been exploring and playing around with and I look forward to sharing some of my discoveries.

The Symmetry Of The Diminished Scale

The diminished scale is ‘symmetrical’ which means that it has a repeating interval pattern that takes you back to where you started.

It’s almost mathematical how it slices up the 12 notes of the piano and always takes you back to the note you started on without changing the alternating interval structure of half and whole steps.

If you start on any note of the piano, and play alternating half/whole steps, there are only 3 possible diminished scales.

Now, each of those 3 diminished scales is related to 4 keys.

Play alternating half/whole steps from C, and you will get back to C. This could be played over C7 to give you a dominant flavour (3 and b7) and also b9, #9, #11, & 13 alterations/extensions.

This exact same scale is the same for Eb, Gb, & A - start on each of those notes, and play alternating half/whole steps, and you will see that you are playing the exact same scale, but starting and ending on a different note in the scale

If you play the exact same scale over C7, Eb7, Gb7 and A7, you will notice that it gives you 3 and b7, and also b9, #9, #11, & 13 alterations/extensions for all of these chords.

The same applies to the other groups:

  • Db, E, G, Bb
  • D, F, Ab, B

First, I’d recommend you learn these groups, so that you can see the relationship described above, which is 1 diminished scale serving 4 keys. So 3 diminished scales serve all 12 keys.

That is the first step for you.

Completely Different to Modes

From now on, look at the diminished scale as a different entity to the scales you are familiar with, such as major scales, and minor scales.

The diminished scale is its own thing. A completely different animal if you like :smile:

And you can superimpose it in many different settings, over lots of different types of chords, always related through the groups highlighted above.

A Nice Analogy - The Human Body

I like how Tuomo referred to it in one of his Masterclass lessons. He said something along the lines of

“diminished is a spine to all harmonic movement”

Let’s continue with this analogy of a body…

Imagine that the major scales are the hands, and the major modes are the fingers.

Imagine that the minor scales are the feet, and the minor modes are the toes.

and then imagine the diminished scale is a deeper, visceral, more integral part of the body system - the spine - which links everything together.

It’s a different system, but still interrelated into all other aspects of harmony.

Does this help? my analogy is a little ‘out there’ :stuck_out_tongue:, but I think that’s a nice way to illustrate where it comes from, what it’s role is, and how it is related to what you already know.

I didn’t want to scare you away with a lot of theory, or application examples, because it’s really hard to explain this clearly without it being overwhelming, particularly in this format. But hopefully you now have a rough idea of what you are dealing with.

I’m still working out the best way to present and teach this, and your question has got my creative juices flowing… so thanks!

I’d also like a dedicated section of the website on diminished, perhaps incorporating the views and insights of all our teachers, all in one place.

More to come…


Hi Hayden, I would definitely be interested in more Diminished.
I have noticed that you mention half/whole steps, but in the 5 Minute masterclass handout and video, the scale pattern is a whole/half step one.
Is there a difference ? :thinking:Do I go up one way, and come back the other way, or does it not matter ?

Many thanks:smiley:

HI Natasha,

My first teacher taught me that there are 2 versions of each diminished scale, half -whole, and whole-half.

In reality, it’s the same scale, and so with the above approach, we have made the topic twice as complex.

All other teachers, mentors, and musicians that I have worked with stick to the fact that there are only 3 diminished scales… which there are. I since realised this is the best way to view the diminished scale.

I mentioned a new diminished section is on our roadmap, and I will redo that tutorial to share my new insights and findings.

Here’s something to play around with…

Take 1 diminished scale C - Db - D# - E - F# - G - A - Bb and back to C

Now this scale works over C7 - Eb7 - Gb7 - A7

Play that scale over each of those 4 chords, are you have R - b9 - #9 - 3 - #11 - 5 - 13 - b7 - R

The Diminished Relationship

Now you can play that exact same scale over Dbdim7, Edim7, Gdim7, & Bbdim7

Any of those diminished chords can function as a rootless b9 chord for all of the chords above (C7 - Eb7 - Gb7 - A7 )

Don’t Run Up & Down The Scale

Finally, remember not to just run up and down the diminished scale, Tuomo touches upon this in his lesson on Diminished Chords here: Diminished Patterns Jazz Piano | Diminished Scale Patterns Licks Rifs Improvisation

Jovino has also created a 5 minute masterclass on Diminished Chords in Brazilian music, I will post this shortly.

Both of these lessons talk about the triads which are inside of each diminished scale, and how these can be used to create more interesting intervals and lines.

Another cool thing is… play any line over any dominant chord, simply move every note in the line up or down a minor 3rd, and you will hear that it works and gives you a hip ‘diminished sound’ - Tuomo also touches upon this in the lesson above.

Diminished is a vast and fascinating subject. Much of this is experimentation Natasha, I will create a dedicated section for further inspiration, but here’s a nice quote I like by Herbie Hancock:

A great teacher is one who realizes that he himself is also a student and whose goal is not dictate the answers, but to stimulate his students creativity enough so that they go out and find the answers themselves.

I often find the gears in my brain “grinding” when I’m working out things on the piano. That is a good thing!

Enjoy this rewarding process of discovery Natasha :blush:

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Hey @natasha0412

I’ve just added a new diminished tutorial by Jovino, check it out here:


He shares some wonderful insights.

The first part of the lesson on ‘softening the landing for 251s’ is super easy to understand and apply.

The second half of the tutorial will require a lot of patience and practice to discover the flavours ‘hidden’ inside of the diminished scale.

This is exactly what I was envisaging with the new teachers… lots of different insights, perspectives, and methods of communicating and displaying the same topic.

I hope you enjoy it.


Here is the download/lesson slides for the above lesson:

Diminished-Masterclass-Jovino.pdf (1.1 MB)

There will be more lessons coming shortly on diminished chords, so stay tuned to explore this fascinating topic.


Hello Hayden and Groovers, I have a question about Diminished theory…

As I understand it, the half-step/ whole step scale gives us the following scale degrees: R - b9, #9, 3, #11, 5, 13, b7 R — no problem

But when I practice my melodic minor scales and get to the V7alt chord I find this : R- b9, - #9,- 3,- b5,- b6- b7- R

What is the difference between the diminished and melodic minor ? Why the differences in these scale degrees ?

I’m very keen to know. Thanks :thinking:

Great question Natasha!

There are some important similarities and differences between those 2 scales. Here are some important points to take into consideration:

1) 8 Note Scale vs. 7 Note Scale

One of the key differences between these scales is the number of notes they contain.

The diminished scales contains 8 notes, whereas the major and minor scales (and their modes) contain 7 notes.

8 note scales - or “octatonic scales” can be useful for playing scale runs, and other melodic ideas in 4/4 time because each note of the scale matches up to an 8th note - or quaver.

2) Similarities To The Altered Mode

As you correctly point out, the diminished scale shares a similar construction to the altered mode.

The altered mode is the 7th mode of the melodic minor scale giving the following scale degrees:

C Altered Mode: R, - b9, - #9, - 3, - b5, - b6, - b7, - R

We could also look at this C Altered Mode as the Db Melodic Minor Scale, played from C to C.

This is 2 ways of looking at the same thing, depending on which method you prefer.

The “Diminished Whole Tone Scale”

Now, if we look at the first 4 notes of the Altered Mode, we can see that it is, in fact, identical to the first 4 notes of the diminished scale:

You may have heard the Altered Mode referred to as the “Diminished Whole Tone Scale” and that is because the 1st half of the Altered Mode is identical to the Diminished Scale, and the last half of the Altered Mode is identical to the Whole Tone Scale.

So that is one of the key similarities between the Altered Mode, & The Diminished Scale - they both share the same 4 starting notes which are R, - b9, - #9, - 3.

3) Differences In Scale Degrees & Application

Next, a key difference between the Altered Mode and the Diminished Scale is the extensions and alterations that are included in each scale, and therefore, the types of harmony that the chord can be applied.

If we just analyse the scales in terms of the extensions & alterations, we get the following:

Altered Mode: b9, - #9, - #11 or b5, - and #5 or b13.
Diminished Scale: b9, - #9, - #11, and natural 13.

The key difference here is that the altered mode contains a #5 or b13 (the same note but musicians refer to it in both ways) and this makes the scale suitable to play over altered harmony.

The word “Altered” in jazz theory is somewhat vague. It implies that the chord contains alterations - usually an altered 9 and an altered 5 - but you can have different combinations of these alterations including:

  • b9, #5,
  • #9, #5

When I play over an altered chord, I will always add in the #5 instead of the natural 5 in my right-hand melodic idea - If I play the 5th that is - I don’t have to include that note in my melody, but if I did, I would favour the #5 over the natural 5.

For me, that is one thing that distinguishes the altered mode from playing the diminished scale over dominant harmony. The diminished scale has the b9 and #9 as we highlighted, but instead, we now have a natural 5 and a natural 6/13. That for me, is the core difference.

Application To Different Chord Types & Qualities:

So now let’s talk about some chord types/qualities, and highlight which of these scales would be more suited from which to derive melodic ideas:

  • C7#5#9 - The altered mode would provide the #5 whereas, the natural 5 and natural 13 in the diminished scale may clash with the underlying harmony; if the #5 is voiced in the chord for example.

  • C13#11 - The diminished scale would be suited here, as it contains the #11 and the natural 13. Whereas, the #5/b13 from the altered mode may clash with the underlying harmony; if the natural 13 or natural 5 is voiced in the chord for example.

  • C7b9 - this is an interesting example, because now we can choose between the 2 scales, both the altered mode, and the diminished scale can be used to access the b9 over a dominant chord, and because we have not specified or included the 5/#5/13 in our left-hand voicing, we then have the freedom to play either melody on top.

That should explain some of the key similarities and differences Natasha. This is a big area of study so let’s continue to develop this thread to incorporate other ideas, perspectives, and ways of looking at this fascinating topic.



Wow @Hayden, thank you so much for explaining this is such amazing detail. Such a lot to learn :slight_smile:

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My pleasure Natasha.

This is just my take on the topic from my experience playing around with these scales.

As always, there are always many different ways of exploring these concepts and ideas. I will speak with our teaching team and we can add more useful insights and perspectives to this thread.

Diminished is such a wonderful topic for us to explore collectively and so thanks for starting this theory thread… I’m sure it will be of interest to all our students and community.

Coming into this area of diminished sound
heres some other video on youtube that i found just now , to expand some ideas around it

michael wolff some nice input and another vision to see how all the scales and diminished chords interact

in this one other vision too and some ideas at the end of applying it

++++ ken hewitt gives here some great ideas of applying it with even leadsheet of them… dont miss it

maybe it can help other members too

Great insight and clear explanation @Hayden on this topic about diminished and their difference with altered scales. All written make things really much more understandable and easier to remember. Thanks

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Nice job compiling these awesome videos Pierre.

Diminished is such a vast and fascinating subject. I think it’s essential to have multiple views and perspectives on the topic.

Let’s continue to build out this thread into the definitive resource on diminished theory on the internet! :sunglasses:

in the lesson on half whole diminished scales https://www.pianogroove.com/jazz-piano-lessons/half-whole-diminished-scale/
there was this comment

_Josh Weissberg, a year ago _
Hi Hayden. On the last ii-v-i progression you played the half whole diminished scale of the ii chord over the entire progression and not just over ii chord. Can you explain the theory behind that? Thanks.

*[Hayden Hill PianoGroove][a year ago]
Hi Josh,

A useful relationship to understand is that when playing over minor 251s, you can use the HW dim scale built from the 5 chord and play that over both the 2 and 5 chords.

The line you are referring to, I transcribed that line from a Kenny Barron recording.

I can’t think of a simple theoretical relationship as to why the notes of E HW Dim work over A7.

But… if you analyse the scale degree of the notes played over A7, we have the 11, 5, b13, b7, root, 5, 11 & #9 (in relation to A7). 3 of the primary chord tones are present (root, 5th and b7) which gives it a strong harmonic foundation. The alterations b13, #9 are also present to add colour.

Another thing that sprung to mind when I transcribed the line was that over A7, he is simply playing the notes of D Dorian, which anticipates the resolution to D-.

However, the biggest ‘takeaway’ I took from transcribing the line, was how he resolves into the 1 Chord… the double grace note into the 9th of D-7 which sounds beautiful.

This is then something that I could apply to any 251.

I was reviewing the diminished lessons and i get this idea :boom: what do you think about @Hayden

The D half whole diminished scale could be considered as the superposition of Ddim chord and the Dbdim chord, as Jovino talk in his 5 minutes masterclass D diminished scales shadow the Db diminished chord which is a A7b9 chords disguised . This could be a smart explanation , not ?

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that is even reverse

so with 251 minor we could play the V diminished scales or the II diminished scales on the 2 and 5 chords

this seems to work with a very special flavour .

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Nice idea Pierre - I find the whole diminished area fascinating.

I understand the connection with Jovino’s “shadow” concept - mainly in terms of voicings - but as you say this could also be applied to right hand melodies and improvisation.

In terms of voicings, if the chord is Ddim7, i can play that with my left hand, and then play notes from the “shadow” in my right hand to get some big and interesting voicing shapes that encompass all notes of the scale.

I have also heard this concept referred to as “Double Diminished” or the “Double Diminished Scale” because the scale is made up of 2 diminished chords a half step apart.

I just tried this and it created some interesting colours:

Over a 251 in D Minor (E-7b5 / A7alt / D-7)

For the E-7b5 and the A7alt chord, I alternated the 2 diminished chords, running up the keyboard, so I played in this order:

  • D-F-Ab-B
  • E-G-Bb-Db
  • F-Ab-B-D
  • G-Bb-Db-E

So basically the right hand just runs up the different inversions of those 2 diminished chords.

And then when I get to the i-7 chord (D-7) I just drop back into the D Dorian mode or the D Melodic Minor/Jazz Minor Mode.

I will have to experiment with this more but I like the idea here.

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Did you watch Tuomo’s lesson on Diminished Scales & Runs …?

Check it out here:

I still need to study this lesson properly when I get the time…

I remember editing it and thinking to myself “I must sit down for a couple hours with this lesson to practice it all” :grinning:

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@Pierrot - I’ve had lots of different musicians explain diminished concepts to me, and some made more sense than others.

I think the best thing is to find as many different ‘views’ or ‘perspectives’ as possible and this will help to build the ‘complete picture’ :sunglasses:


oh thanks ! i would have miss this one :astonished:

the tool search from the site with ’ diminished’ dont point to it … maybe a tag missing ?

very dense and interesting again … wow great sound with easy ideas … love that so much (but Tuomo applying this always so fast, i need 3 times reviewing it to understand , hopefully it is recorded :smile: )

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Prior to developing my interest in Brazilian music (thanks mainly to Jovino’s totes awesome material in PG), I had never had occasion really to pay much attention to diminished chords, and then diminished scales.

You would periodically get a diminished triad in the types of more ‘soulful’ and jazz flavoured rock that I dig (Steely Dan, Boz Scaggs and the Doobie Brothers have all used them), and in a funk context from the likes of the Average White Band (half and whole diminished 7’s). A quote that sticks in my mind from when I first set out teaching myself music about 4 years ago came from a no doubt well-intentioned approach, but described it as the chord ‘you wouldn’t take home to meet your mother’! Not to mention the variations on the ‘ugly’ chord theme!

But I now love the sound especially within a Bossa Nova context. It does sound slightly questioning and an ‘unsure’ colour as a type of harmony, and can sound a little spacey and ethereal at times too, depending on the voicing. I must admit I do find if I want to soften the sound, and depending on the voice leading, I do add a whole note above one of the tones

When I have more time I am for sure going to be focusing on this! thanks for the reminders all about the location of the lessons :smiley:

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I’ll look into that… thanks! :ok_hand:

Yes you will notice some similarities with Jovino’s lesson, and some different perspectives too.

For me, that’s the fascinating thing about diminished theory - and jazz theory in general - that there is lots of different ways of looking at the same thing.

I always communicate to our teachers to play and demonstrate slowly… but sometimes this is easier said than done I think! At least we have the slow down controls :grinning: