The Secrets of Learning the Fretboard

Diminished Chords

Diminished Chords Feature Image

Learn diminished and diminished seventh chord grips, how they’re constructed, and when to use them.  You’ll learn how dim7 chords form a fun pattern that can be played in many locations.

Diminished chords have a dissonant sound.  There is a lot of tension.  It is primarily used in Jazz styles.

Diminished Chord Formula

In major keys, the diminished chord is built off the 7th degree of the major scale.

If you construct a diminished chord from its parallel major scale (ex: C dim from the C major scale), you would use the following pattern.

Diminished Chord Formula:  1-♭3-♭5

If you want a plain diminished chord, all you have to do is remove the VI note, or learn a movable pattern (just like any other chord) as shown below. (R= Root note)

Diminished Patterns

There are a lot of playable diminished patterns.  I provided 9 of them.  You’ll notice a lot of similarities among them.  You’ll see in a moment that the Dim7 patterns are actually easier to use.

Diminished Chord Grip Rooted on 6th StringDiminished Chord Grip Rooted on 5th String Diminished Chord Grip Rooted on 5th StringDiminished Chord Grip Rooted on 5th StringDiminished Chord Grip Rooted on 4th StringDiminished Chord Grip Rooted on 3rd String Diminished Chord Grip Rooted on 2nd String  Diminished Chord Grip Rooted on 2nd String    Diminished Chord Grip Rooted on 2nd String

Diminished Seventh Chord Formula

The diminished 7th chord adds a double-flatted 7th to the diminished chord to form the following pattern.

Diminished 7th Chord Formula: 1-♭3-♭5-♭♭7

Cdim7 = C-E♭-G♭-B♭♭

You will notice that a ♭♭7 is the same pitch as the 6.  In other words, B♭♭ is enharmonic with A.  The use of a double flat ensures we are communicating the notes properly.

For practical purposes, you can use the chord formula: 1-♭3-♭5-6.

Diminished Intervals

Diminished chords are constructed of minor third intervals.

  • C to E♭ is a minor third
  • E♭ to G♭ is a minor third
  • G♭ to B♭♭ (or A) is a minor third
  • B♭♭ (A) to C is a minor third

Any of the four notes (for dim7 chords) can be the root note.  Perhaps that is why it sounds so dissonant. It also means the next pattern is only a minor third (3 frets away).

Drop-2 Diminished 7th Patterns

Diminished Chord Pattern Low StringsDiminished Chord Pattern Middle Strings Diminished Chord Pattern High Strings

Diminished 7 Chord Shift

You’ll notice in the two examples below that you can move the dim7 pattern up 3 frets to find another dim7 chord with the same exact notes.  It is simply a different voicing.  In other words, you have 4 voicings per grip!  This is incredibly useful.

Shift Example 1

Cdim7 Shift 1aCdim7 Shift 2a

Shift Example 2

Cdim7 Shift 1b Cdim7 Shift 2b

 How the Diminished 7 Chord is Used

Diminished chords are not used very often.  They can be used in a major key, but this is not common.  If they are, it is based on the 7th degree of the scale.  In the key of C, this would be Bdim.  Diminished chord theory is a topic worthy of its own lesson (or course), but I will try to explain one of the primary uses in Jazz, which is as a chord substitution.

Diminished 7 chords are used as chord substitutions for Dominant7♭9 chords.  Actually, diminished 7 chords substitute for four different 7♭9 chords.

Why the Substitution Works

Let’s look at the 7♭9 chord formula: 1-3-5-♭7-♭9

Notice this pattern:

  • 3rd to 5th is a minor third.
  • 5th to ♭7 is a minor third.
  • ♭7 to ♭9 is a minor third.

Those are the same intervals as the dim7 chord.  If you add a root note, which is usually played by a bass player, you have a 7♭9 chord.  Consider that we know the diminished 7 chord voicings are interchangable.  This means that you can find a root note by going down a major third from any note.

Cdim7 has the following notes C-E♭-G♭-A

  • A♭ is a major third (2 steps) down from C, therefore we can substitute for A♭7♭9
  • B is a major third down from E♭, therefore you can substitute for B7♭9
  • D is a major third down from G♭, therefore you can substitute for D7♭9
  • F is a major third down from A, therefore you can substitute for F7♭9

We’re figuring this out backwards.  The easiest way to learn this substitution is to take the root note of the 7♭9 chord, raise it by a semitone (1/2 step) and play that diminished chord.  It works every time due to the symmetry of the dim7 chord.

  • A♭7♭9 would use the Adim7 chord substitution.
  • B7♭9 would use the Cdim7 chord substitution.
  • D7♭9 would use the E♭dim7 chord substitution.
  • F7♭9 would use the G♭dim7 chord substitution.

Of course, we know that Adim7, Cdim7, E♭dim7, and G♭dim7 use the same notes, so they’re completely interchangable.

When are 7♭9 Chords Used?

They are primarily used in diminished harmonies, which is a lesson or course in itself, but you may be able to incorporate them into your playing.

Since these are dominant chords, they want to resolve down a perfect fifth or up a perfect fourth.  So you can resolve these down to one of four different chords.

  • A♭7♭9 resolves to D♭maj7
  • B7♭9 resolves to Emaj7
  • D7♭9 resolves to Gmaj7
  • F7♭9 resolves to B♭maj7

You will notice that they resolve 1/2 step up from any of the diminished chord notes.

  • D♭maj7 is a semitone higher than C
  • Emaj7 is a semitone higher than E♭
  • Gmaj7 is a semitone higher than G♭
  • B♭maj7 is a semitone higher than A

What this means it that you can literally change keys when one of these chords shows up.  We just learned that Cdim7, E♭dim7, G♭dim7, and Adim7 are enharmonically the same chord and that they resolve to four different major chords: D♭, E, G, and B♭.  In other words,  you can substitute a dim7 for your V7 chord if you’re willing to put up with one out-of-key note.  It will give a diminished that that works well.

Example of Changing Keys with Diminished Chords

Let’s assume we’re in the key of E.  Our Cdim7, E♭dim7, G♭dim7, and Adim7 (which is the same chord) resolves to E.  One of these four, E♭ is only a 1/2 step down, which is enharmonic with the 7th of E, D♯.   This is an easy way to remember it.  You can also play the ii-dim7 or the iv-dim7, which are also in our set of four.

The following example is a simple ii-V-I with the vii-dim7 substituted for the V chord.

Diminished Chord Substitution


Diminished chords are fun because of their symmetry.  They are also flat-out dissonant, but they can resolve nicely if you use them well.  The fact that you can change keys (as shown) is a fun nuance.  Enjoy!

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About Patrick MacFarlane 127 Articles
I've been teaching guitar online for 25 years. My site has been featured in Rolling Stone and Acoustic Guitar magazine. I'm the author of The Secrets of Learning the Fretboard and Guitar Lesson World The Book.

16 Comments on Diminished Chords

  1. Very helpful. I’m just getting into both diminished and 7th chords and was having to look them continuously in my ‘book of chords’. This will make it much easier. Especially, understanding the 6th note relationship.
    Thank You

  2. I just signed up.I read your lesson on dim chords and it was quite informative. I don’t quite understand it all, but after another read through (or two, three) I’ll get it. Very well written. I look forward to more!!;

    • I’m glad you liked the article! Feel free to email me your questions through my contact page. I’ll do my best to clarify and it’ll help me ensure the article is easily understood for other readers.

  3. Still doesn’t help me understand the difference between C7b9, C7+9, and Cdim – they are all diminished chords, but I’ve been searching for months for a decent explanation of the difference – but not one single explanation has yet been forthcoming. Maybe that’s why Jazz is so hard – it seems like a closely guarded secret.

    • Diminished chords are confusing to most. I’ll try to make it clearer. If you omit the C from C7b9 (C Db E G Bb), you have a dim7 chord. Since the bass player usually plays the root, you don’t need to worry about that note. C7+9 is a C7 chord with an augmented 9th (C D# E G Bb). It contains Edim but not a dim7 chord. Cdim is simply C Eb Gb. To go into greater depth, I’d need to know the context.

      I hope this helps!

  4. Hi Patrick I’m a newby my name is tony could do something on augmented chords or the theroy on them thanks I’m hooked go head and reel me in thanks sir

  5. What amazing secret I’ve just completely discovered concerning the 5dim and 7dim chords! A few hours ago they were just useless to me as an ambitious guitarist but now my confidence is suddenly build up by your simple yet very understandable explanation

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