While major and minor chords get all the attention, don’t neglect music’s lovely diminished chords. They can spice up your boring chord progressions and add drama to your songs.
Although staples of jazz, blues, and classical music, diminished chords aren’t used very often in pop, rock, or country. That’s a shame, because diminished chords are incredibly versatile and can add just the right amount of tension to your songs to keep things interesting.
What is a diminished chord?
A diminished triad is the more-dissonant sibling of a minor chord. It is formed by stacking two minor thirds on top of each other. So where a C minor chord is spelled C-Eb-G, a C diminished chord contains the notes C-Eb-Gb. (In other words, take a minor chord and flatten the fifth note.) It is notated as Cdim or Cº.
The diminished seventh chord
Although diminished chords do exist in the wild as simple triads, you are more likely to hear them in their diminished seventh form. Diminished chords and their seventh counterparts can be used interchangeably, and because diminished seventh chords are easier to play on guitar, most guitarists simply use the seventh instead of the triad.
To create a diminished seventh chord — also known as a fully diminished seventh — you stack three minor thirds on top of each other. So, a C diminished seventh (also notated as Cdim7 or Cº7) is spelled C-Eb-Gb-Bbb. (And no, that’s not a typo, that’s B-double-flat—a note that is exactly the same as A, so that’s how we’re going to refer to it from now on.)
How diminished chords are used
Diminished chords (and diminished sevenths) tend to want to resolve to the chord one semitone above them. So, a Bº7 will want to resolve to C. (By the way, that Bº7 can resolve to either C major or C minor, it doesn’t matter. This is part of what makes diminished chords so versatile.)
They are often used as passing chords, pulling the listener from one chord to another. For example, if you want to go from a C major chord to a D major chord, you use a C#dim chord to increase the tension between the two. Notice how the bass note walks up the chromatic scale:
Elton John’s “Benny and the Jets” provides a good example of this. You can hear, at 0:33 into the song, how that G#dim7 chord pulls you up to the Am.
Hey kids, shake it loose together,
the spotlight´s hitting something
that´s been known to change the weather
We´ll kill the fatted calf tonight…
As we saw with augmented chords, diminished chords are symmetrical. In other words, Cº7, Ebº7, Gbº7, and Aº7 all use the same four notes:
Cº7 = C-Eb-Gb-A
Ebº7 = Eb-Gb-A-C
Gbº7 = Gb-A-C-Eb
Aº7 = A-C-Eb-Gb
That means there are really only three different groups of diminished seventh chords, with the second two groups spelled out below.
C#º7 = C#-E-G-Bb
Eº7 = E-G-Bb-C#
Gº7 = G-Bb-C#-E
Bbº7 = Bb-C#-E-G
Dº7 = D-F-Ab-B
Fº7 = F-Ab-B-D
Abº7 = Ab-B-D-F
Bº7 = B-D-F-Ab
You can hear a good example of the symmetrical nature of diminished chords in “Michelle” by the Beatles, in which the guitar plays Abº7→Bº7→Dº7→Bº7 before finally resolving up to C major over the words “go together well,” at 0:14 in the video below.
Due to the symmetrical quality of diminished sevenths, and because these chords want to resolve to the chord one semitone above them, the same four notes can easily resolve to eight different chords:
Cº7→C# (major or minor)
Ebº7→E (major or minor)
Gbº7→G (major or minor)
Aº7→Bb (major or minor)
You can vacillate between a major chord and its own diminished seventh. For example, C→Cº7→C. You can hear examples of this in Queen’s Bohemian Rhapsody in this section (3:07 in the video below)
D A Aº A D A Aº
I see a little silhouetto of a man.
And then again at 3:25 in the video…
Ab/Eb Eb Ebº Eb Ab/Eb Eb Ebº Eb
He’s just a poor boy from a poor fam-i-ly.
Actually, diminished chords are all over that song (and many other songs in Queen’s catalog. Diminished chords are part of what makes their music so dramatic). Here is a link to all the chords in “Bohemian Rhapsody.”
Other uses for diminished chords
In George Harrison’s “My Sweet Lord,” Harrison wants to get from the I chord (an E) to the ii (an F#m) on the phrase “…see you Lord, but it takes so long, my Lord.” To do this he could just go from E→Fº7→F#m, but he throws in an extra chord, a C#7 (the V-of-ii chord).
Really want to see you lord
Fº7 C#7 F#m
But it takes so long, my lord…
This progression works because of the simultaneous ascending (see red notes below) and descending (blue notes below) lines.
E maj = E-G#-B-E
Fº7 (Dº7) = F-G#-B-D
C#7 = F-G#-B-C# (Yes, that F is technically an E#, but let’s not nitpick)
F#m = F#-A-C#
You can hear this passage at 0:51 in the video
The diminished scale
You can form a highly useful octatonic scale by combining two diminished seventh chords; for example: Cº7 and Dº7. This would give you a scale that includes the following notes: C, D, Eb, F, Gb, Ab, A, B. This is a symmetrical scale that follows the pattern of whole-tone, semitone, whole-tone, semitone, etc.
The diminished scale is useful for improvisational and compositional purposes over the dominant seventh chord. The way you employ it is by starting your scale one semitone above the dominant seventh chord. So, if we’re in the key of C, our dominant seventh chord is G7. We can therefore improvise (or compose) on the G# diminished scale. For more info on the diminished scale, visit this website.
The half-diminished chord
Also known as a minor-seventh-flat-five, the half-diminished chord is similar to a fully diminished seventh chord, except that you’re adding a flat-seven instead of a diminished seven.
A Cº7 = C-Eb-Gb-Bbb (A)
A C half-diminished = C-Eb-Gb-Bb
The half-diminished chord is sometimes noted as ø7, but you are much more likely to see this chord labeled as m7b5 or even m7-5.
In fact, it’s probably more helpful to think of this chord as a zestier version of a minor seventh than as a diminished chord because of the way it’s used. The half-diminished doesn’t want to resolve up a semitone the way its fully diminished sibling does. Instead, it is most often used as a substitute for a ii chord in the classic ii-V-I progression. So you have ii7-5→V7→I (in the key of C: Dm7-5→G7→C).
A classic example of this is in Gloria Gaynor’s “I Will Survive,” which can be heard at 0:14 in the video.
But then I spent so many nights thinking how you did me wrong
And I grew strong, I learned how to get along
And so you’re back…
Have fun experimenting!
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