You are currently viewing The Diminished Chord (Dom 7th Chord Substitute)

The Diminished Chord (Dom 7th Chord Substitute)

Beginner guitar players’ eyes glaze over if you mention any type of diminished chord or the Locrian mode. But there are a lot of simple tricks and juicy licks when you use diminished chords. I take the mystery out of the diminished chords built from the Locrian mode and show you how they are just substitutes for dominant 7th chords.


The Locrian Diminished Chord

There are two chords built on the 7th scale degree of the major scale that are common in popular music. The diminished triad and the half-diminished chord also called minor 7 flat 5 chord. In actually, those 2 chords are rare in some genres but you do see them in rock and blues.

The other common diminished chord is the fully diminished chord or dim7. You can not build that chord from the major scale so I won’t be covering it here.

The 3rd Locrian diminished chord: m11♭5

There is another diminished chord worth covering that can be built from the Locrian mode: the minor 11 flat 5 (m11♭5). Believe me, you will most likely never see the m11♭5 chord. However, it is in the song  “If You Really Love Me” by Stevie Wonder. I cover why this chord is worth considering in my Altered Chords article, but here is a simple breakdown on all 3 chords:

Dim triad = substitute for the V7 chord (e.g., Bdim for G7)

m7♭5 = substitute for the V9 chord (Bm7♭5 for G9)

m11♭5 = substitute for the V9/13 chord (Bm11♭5 for G9/13)

The dominant 9/13 is usually notated as a 13 chord but it includes the 9. And it’s always shown without the perfect 5th. If you play that chord with the 5th but drop the root, then it equals the m11♭5 chord.

If you play the B Blues scale without the perfect 5th (B Locrian pentatonic) it equals the notes in a Bm11♭5 chord. The take away here is that you can play the B Locrian pentatonic or the Bm11♭5 chord in place of a G7 dominant chord.

So a great substitute for a dom9 or dom13 chord is the blues scale without the P5 (Locrian pentatonic) on the major third of the dom7 chord. So B Locrian pentatonic instead of G7 to resolve to C, Cmaj7, C6, etc.

Here are some closed diminished chord shapes and my chord symbol diagram for reference:

Explanation of the symbols used on my chord blocks


diminished triad E/G voicing
diminished triad D voicing
diminished triad C voicing
half-diminished chord A voicing


half-diminished chord D voicing
half-diminished chord G voicing
half-diminished chord G voicing variation
m11b5 D voicing


All of these chords are great dominant 7th substitutions. Some of them are excellent for moving to other positions for chord partials and guitar licks. Hopefully, you can see the minor shapes and major 6th intervals. If you know the other triads from the major scale, then you should know how to use those shapes. The m115 chord though is a little harder to apply.


The 6 best major keys for open chords

The open strings on the guitar are tuned to E, A, D, G, B, and E (standard tuning). The best major scale keys that use open chords are C, G, and D major. They are the only major scale keys that contain the notes, E, A, D, G, & B.

The next 3 major scales that are great for open chords are F major, A major and E major each with “avoid” strings:

F major: the perfect 4th is B♭ so the open B string has to be fretted or muted.

A major: the major 7th is G# so the open G has to be fretted or muted unless you are playing A blues.

E major: the major 3rd is G# and the major 7th is D# so the open G and D strings have to be fretted or muted unless you are playing E blues.

Since my site is based around guitar chords, and I prefer open chords, they are the only 6 keys I cover in this article. And by the way, the open B string is the ♭5 for F so you can use that string in F major blues songs. STOPPED


C major: B Locrian diminished chord

Here are the three diminished chords for B Locrian compared to three G7 dominant chords in 1st inversion. Are you familiar with chord inversions? Simply put, chord inversions refer to having a chord tone other than the root note in the bass. Fist inversion chords have the 3rd of the chord in the bass, which is B for G major chords.

B-D-F = 1-♭3-♭5 = B dim
B-D-F-G = 3-5-♭7-1 = G7 1st inversion

B-D-F-A =1-♭3-♭5-♭7 = Bm7♭5
B-D-F-A-G = 3-5-♭7-9-1 = G9 1st inversion

B-D-F-A-E = 1-♭3-♭5-♭7-11 = Bm11♭5 = B Locrian pentatonic = B Blues scale no fifth
B-D-F-A-E-G = 3-5-♭7-9-13-1 = G9/13 1st inversion

Do you see it? The relationship between the vii dim chords and the V7 chords? You can just skip the diminished chords and play the dominant 7th chords. However, the diminished chords have 1 less note and therefore are easier to hold.

Here are my two favorite open B diminished chords:


Bm7v5 chord 1st position
Bm11b5 guitar chord 1st position



But what does that mean? Diminished chords and scale guitar tricks

The trick, or hack, that a lot of guitar players use is to substitute the diminished chords for dominant 7th chords. Plus there is the benefit of creating licks from the diminished chord shapes. Since diminished chords are easier to hold than their dom7 counterparts, you have an extra finger or two for embellishments.

Here is a simple lick that starts on a Bdim triad and goes to a partial C add9 chord.

B dim triad riff
My favorite diminished chord shape going to a C add9 riff


Check out the 1st m7♭5 chord shape above. The ♭5, ♭7 and ♭3 of the chord shape is a minor triad or a 6 chord without the 5th. If that was a Bm7♭5, then those notes would be F-A-D which is a Dm chord (F6 no 5).

Try sliding that shape up a whole step for a G6 chord without the 5th. That riff sounds great. So that would be a Bdim chord substituting for a G9 chord then slide it up for a G6 and you’re still on a G chord. That’s just one example of the versatility of diminished chords!


G major: F# Locrian diminished chords

The diminished chords in G major are F#dim, F#m7♭5, and F#m11♭5, which can substitute for D7, D9, and D9/13. The F#dim chord is limited with only the open A string, but the other 2 chords have better open chord options.

F#-A-C = F# dim
F#-A-C-D = D7

F#-A-C-E = F#m7♭5
F#-A-C-E-D = D9

F#-A-C-E-B = F#m11♭5
F#-A-C-E-B-D = D9/13


F# diminished triad 7th position
F#m7b5 chord 1st position
F#m7b5 8th position
F#m11b5 1st position



D major: C# diminished chords

The diminished chords in D major are C#dim, C#m7♭5, and C#m11♭5, which can substitute for A7, A9, and A9/13. There are plenty of open strings in these chords.

C#-E-G = C# dim
C#-E-G-A = A7

C#-E-G-B = C#m7♭5
C#-E-G-B-A = A9

C#-E-G-B-F# = C#m11♭5
C#-E-G-B-F#-A = A9/13

Here is a riff going from an A7 chord to a C#dim.

C sharp diminished triad riff


A major: G# diminished chords

The diminished chords in A major are G#dim, G#m7♭5, and G#m11♭5, which can substitute for E7, E9, and E9/13. The only open strings available for the G#dim chords are the B and D strings.

G#-B-D = G# dim
G#-B-D-E = E7

G#-B-D-F# = G#m7♭5
G#-B-D-F#-E = E9

G#-B-D-F#-C# = G#m11♭5
G#-B-D-F#-C#-E = E9/13

Here is my favorite open G# half-diminished chord.

G# m7b5 chord


E major: D# diminished chords

The diminished chords in E major are D#dim, D#m7♭5, and D#m11♭5, which can substitute for B7, B9, and B9/13. The problem with the diminished chords here is that you only have 1 open string. So you need to use either closed chords or switch to B7 chords.

D#-F#-A = D# dim
D#-F#-A-B = B7

D#-F#-A-C# = D#m7♭5
D#-F#-A-C#-B = B9

D#-F#-A-C#-G# = D#m11♭5
D#-F#-A-C#-G#-B = B9/13

D#m11b5 chord progression example
A simple chord progression in E major with a D#m11b5 chord


F major: E diminished chords

The diminished chords in F major are Edim, Em7♭5, and Em11♭5, which can substitute for C7, C9, and C9/13. The Edim triad is limited with only the open G and E strings, but the Em7b5 and Em11b5 have more options.

E-G-Bb = E dim
E-G-Bb-C = C7

E-G-Bb-D = Em7♭5
E-G-Bb-D-C = C9

E-G-Bb-D-A = Em11♭5
E-G-Bb-D-A-C = C9/13

Here is an open Em11♭5 chord and a scale for an open E Locrian pentatonic scale. Both sound great and would be good over a C7 chord, even better over a C9 or C13 chord. Remember, don’t the B note of the E blues scale. I added the slash on the C note of the B string to give you a 2nd note to play.

Em11b5 chord 1st position
E Locrian pentatonic scale


Final Thoughts

So what are the important points in this article?

  1. If you are just starting out writing songs then just stick with the 7th chords.
  2. Look into the dim triad, m7♭5 chords, and the Locrian pentatonic scale if you write a lot of blues tunes.
  3. If you are an intermediate or advanced guitar player then go hog wild with the dissonance and resolution tied to the diminished chords.

Check out the Wikipedia page on the Diminished Triad which has links to some other diminished chords for more information on diminished chords. Also, read my article on all the other diminished chords not covered here.