The Diminished Chord
The diminished chord is built out of minor 3rds (3 semitones). Because an octave is 12 semitones, stacking further minor 3rd above the top note of a diminished chord just repeats the same existing notes (D → F → A♭ → B → D → F → A♭ → B → D → etc.). Because of this the diminished chord repeats at intervals of minor thirds. This means there are only 3 unique diminished chords:
- Cdim7 = E♭dim7 = G♭dim7 = Adim7
- D♭dim7 = Edim7 = Gdim7 = B♭dim7
- Ddim7 = Fdim7 = A♭dim7 = Bdim7
The Diminished Scale
The Diminished Scale is:
- An Octatonic Scale (i.e. it has 8 notes)
- A Symmetrical Scale (i.e. the intervals repeat in a pattern)
Because it is a symmetrical scale (and much like the diminished chord) there are only three unique diminished scales:
- C = E♭ = G♭ = A diminished scale
- D♭ = E = G = B♭ diminished scale
- D = F = A♭ = B diminished scale
There are, however, two possible modes of each diminished scale. And they get their names from the interval pattern that create them. These are:
- The Half-Whole (H/W) Diminished Scale
- Interval Pattern: semitone – tone – semitone – tone – …etc.
- Used over a V7 chord
- The Whole-Half (W/H) Diminished Scale
- Interval Pattern: tone – semitone – tone – semitone – …etc.
- Used over a Diminished chord
| Scale | Chord | Notes & Degrees | |||||||
|---|---|---|---|---|---|---|---|---|---|
| C H/W Dim | C13b9#9#11 OR C7b9 | C | D♭ | D# | E | F# | G | A | B♭ |
| 1 | ♭9 | #9 | 3 | #11 | 5 | 13 | ♭7 | ||
| D♭ W/H Dim | D♭dim7 | D♭ | D# | E | F# | G | A | B♭ | C |
| 1 | + 1 tone | ♭3 | + 1 tone | ♭5 | + 1 tone | ♭♭7 | + 1 tone | ||
Notice that:
- The C H/W = D♭W/H Diminished Scales (i.e. they are modes);
- The chord from the C H/W Diminished Scale is a C7♭9 (C E G B♭ D♭);
- The chord from the D♭W/H Diminished Scale is a D♭dim7 (D♭ E G B♭)
- D♭dim7 = Rootless C7♭9.
The H/W Diminished Scale and/or associated chord can be substituted in place of a V7 chord. While, the Whole-Half Diminished Scale is used over a diminished chord. For example:
| Chord Progression | D♭o7 | Gm7 | C7 (or C7♭9) | FMaj7 |
|---|---|---|---|---|
| Scales | D♭ W/H Diminished | G Dorian | C H/W Diminished | F Ionian |
Now, remember that the diminished chord and scale repeat at intervals of minor 3rds. This means that:
- C H/W = E♭ H/W = G♭ H/W = A H/W = D♭ W/H = E W/H = G W/H = B♭ W/H
Diminished Lick
Below is a classic diminished lick in B♭ H/W Diminished Scale. Try it out and listen to how it sounds.
Associated Chords
Just like with regular diatonic scales, we can assign each note in the diminished scale an associated chord. This gives us:
| Scale | Scale Chords | |||||||
|---|---|---|---|---|---|---|---|---|
| C H/W Diminished | C7♭9 | D♭o7 | D#7♭9 | Eo7 | F#7♭9 | Go7 | A7♭9 | B♭o7 |
No Avoid Notes and Interchangeability of Chords
Just like the Melodic Minor and Wholetone scale, the Diminished Scale has no avoid notes. This means that all of the above chords are completely interchangeable. Playing a D♭dim7 chord is effectively like playing all eight of the above chords at once.
| Chord | D♭ | E | G | B♭ |
|---|---|---|---|---|
| D♭o7 = Eo7 = Go7 = B♭o7 | Diminished Chord | |||
| C7♭9 | ♭9 | 3 | 5 | ♭7 |
| D#7♭9 | ♭7 | ♭9 | 3 | 5 |
| F#7♭9 | 5 | ♭7 | ♭9 | 3 |
| A7♭9 | 3 | 5 | ♭7 | ♭9 |
Altered Diminished Chord
Interestingly, if you move any note in a diminished chord up a whole-step, you still remain within the Diminished Scale – so you still have a diminished chord. I will call this the Altered Diminished Chord. You can substitute this new note in whenever you have a diminished chord. This greatly increases the tension of the chord which can make it sound really interesting and jazzy.
| D♭o7 | D♭ | E | G | B♭ |
|---|---|---|---|---|
| Change note to | D# | F# | A | C |
| Chord | Diminished | Altered Diminished |
|---|---|---|
| A♭o7 | A♭ B D F | A♭ B D G |
| A♭ B E F | ||
| A♭ C# D F | ||
| B♭ B D F |
Taking this to the extreme, you can also move ALL the notes up a whole-step and play a D#dim7 chord instead of a D♭dim7 chord. This will sound incredibly dissonant, but it’s theoretically correct.
Double Diminished Chord
You may have also noticed that the Diminished Scale is really just two Diminished Chords a semitone apart, superimposed over each other. Using this idea allows you to create something called a Double Diminished Chord.
If you play a D♭dim7 chord in your left hand and a Cdim7 chord in your right hand, you have yourself a Double Diminished Chord. This is a very jazzy and dissonant sound which can actually be a number of different chords at once. These are listed below.
| Voicing | Chord | Notes | Combined Chord |
|---|---|---|---|
| Left Hand | D♭o7 | D♭ E G B♭ | C13♭9#9#11 D#13♭9#9#11 F#13♭9#9#11 A13♭9#9#11 |
| Right Hand | Co7 | C E♭ G♭ A |
Have a Listen to
- Moment’s Notice ~ John Coltrane (Coltrane’s solo at about 2:07)
- Caravan ~ Duke Ellington
- Freedom Jazz Dance ~ Covered by Miles Davis’ Second Great Quintet (Hancock’s solo at 4:50)
- Dolphin Dance ~ Herbie Hancock