diminished seventh chords

So, is this fully diminished ( dim ) seventh chord essential to the music you are creating? Maybe yes, maybe no eh? If your a jazz player and depending on your style, you might use this chord a couple of times, in a couple of different places, in each song you play. If your a blues artist or rocker, you might use this chord once per week. Folk and country players maybe once a month. For the jazz artist studying and performing jazz standards, the diminished seventh chord will potentially become an essential color on their palette. For not only is it perhaps the "ultimate passing chord of all time", but the theoretical properties associated with the diminished color can create a large and relatively easily entered musical door, which connects a more diatonic, tonally based environment into the polytonal universe. Really? Without a doubt, understanding the theory of the diminished seventh chord can be an essential step for the emerging jazz artist. So, if your art leans in a jazzy way, or perhaps you are a blues, rock, country or folk artist looking to expand your palette with some jazzy colors, right on, I mean, read on!

Is there an organic source for the diminished seventh chord within equal temper? Yep, although it's kinda buried deep within the system, we can diatonically create the fully diminished chord from a couple of sources. First, let's hear the evolution of a vanilla tonic major seventh color through the various chord type colors and arrive at the diminished seventh chord. Example 1.

Hear the de-evolution of chord quality and tonal stability? We achieve this by simply lowering pitches in each successive chord to arrive at the diminished chord. Here is a chart spelling out the pitches used to create the above chords. Are you hip to spelling chords? Example 1a.

As we can see in the above chart of pitches, we gradually "diminish" or reduce in size, the 3rd, 5th and 7th chord degrees, until we reach the diminished sound, sort of the end of the line. Any further pitch reduction moving the discussion out of tertian harmony. Can you see the interval symmetry between the pitches of the C diminished chord? All minor 3rds.

There are two organic sources for the fully diminished seventh chord from within the equal tempered system of tonal organization. And as they are quite a bit different in their theory, it is probably best to examine each one separately. One organic source of the diminished color comes from the harmonic minor scale. Are you hip to this color? Here is its sound. Example 2.

The harmonic minor color could be viewed simply as a simple variation of the natural minor group of pitches, generally a much more common sound. Let's start with the natural minor color and work our way through the theory to create the diminished color. Here are the pitches of the natural minor scale using the pitch C as the root. Example 2a.

To evolve the harmonic minor color from the natural minor grouping, we simply raise the 7th degree by half step, creating a leading tone seventh within the group. This simple raising of the 7th degree by half step creates some interesting diatonic possibilities. Example 2b.

Compare these two groups of pitches which create the minor tonality. Example 2c.

Cool so far? The harmonic minor does have a bit of the "gypsy" flavor no? Either way, it is within this harmonic minor group that we can diatonically create the fully diminished seventh chord. How? Well, let's create the arpeggio of the C harmonic minor grouping of pitches and spell the chords. Example 2d.

See the pitches of the diminished chord? Which scale degree? Can you see the chord spelt with consecutive intervals of the minor 3rd between the pitches? Got it? Right, on the seventh scale degree of the harmonic minor scale we can diatonically create the fully diminished seventh chord. Easy enough eh? Here is the sound of the chords from the above chart. Example 2e.

Dig the sounds, some interesting colors for the minor tonality no? Here the diminished chord in bar 17? Lets place the diminished color into the natural minor tonality. Example 2f.

Nice fit huh? Dig the upper pedal? So, even though the fully diminished 7th chord is not diatonic to the natural minor, still works perfect? Exactly. So much of the creation of the various American styles of music is in borrowing elements. A second key factor from the harmonic minor is that the chord built on the 5th scale degree is a dominant seventh chord, not a diatonic minor seventh, as found in the natural minor color. Big difference? Theory wise potentially yes. Thanks to the leading tone within the harmonic minor group, we can utilize this important color diatonically in the minor tonality. We'll soon be needing this chord to understand a crucial property of the diminished group. 

Are you o.k. with the numerical representations of the chords? "V 7" instead of "G 7?" Theorists like to use these numerical symbols in that they "genericize" a chord to facilitate discussion of a chords theoretical properties. So when we discuss the virtues of a V 7 chord type instead of G 7 chord, we can apply those principles to any of the 12 "V 7" chords available from the chromatic scale. Cool with this? A simple but big step of consciousness for the emerging theorist.

A second way to organically derive the fully diminished seventh chord is from the symmetrical / hybrid diminished scale. Hip to this critter? Here's a quick review. Let's build a B diminished scale. Example 3.

See how the scale is created? Simply by alternating between whole steps and half steps, the repetition of which builds this symmetrical diminished loop of pitches. The B diminished arpeggio or chord leaps out of the above chart of pitches, leaving behind a fully diminished seventh arpeggio from the root C#? Holy cow, that's cool. So two fully diminished arpeggios within the one diminished scale? You got it. If all of the pitches of the B diminished chord are a minor third interval apart, can each of these pitches function as the root of the chord? Exactly. Compare the following diminished chord voicings, all created from the one diminished chord. Example 3a. 

Cool with this? Sound alike? Yes? Then dig this ... If all of the pitches can function as the root of the chord and the pitch B is the leading tone to C, as discussed above in example 1c, are the other 3 pitches of this fully diminished 7th chord also leading tones to 3 other keys? And ... are the associated resolving key centers also a minor third interval apart ...?

You betcha... yes to all of the above! With this simple theoretical property of each pitch of the fully diminished seventh chord being a potential root or leading tone of the chord, based on the minor third interval / symmetrical structure of the diminished group, our ability to fine tune how we create and release musical tension in our artistic creations can take a giant step forward. Of course, which direction this step goes depends on one's artistic aspirations. But regardless of which way we go artistically, the coolness in the diminished chord theory and it's potential applications opens upon a vista of unsurpassed theoretical beauty as well as a sure pathway towards the realm of polytonality.

So, two organic sources of the fully diminished seventh chord from within the equal tempered system, whose pitches are all potential roots of other chords and leading tones to other tonal destinations. We gotta explore this some more. Roots first then destinations.

When a diminished chord, or any chord for that matter, is named by the root of the chord, nine times out of ten the root or bass pitch of the chord is an integral part in the chord progression of the music it is being used within. For example, we commonly find the C # diminished seventh chord between the tonic and Two chord in the key of C major. Numerically known as the "sharp One diminished", the " # i dim 7 " operates as a passing chord linking two diatonic elements. Example 3b.

Cool with this? Inserting the C # in the bass adds a bit of the chromatic color to the show, oftentimes increasing the sense of foreword motion of the music. We commonly find root position fully diminished seventh chords between most of the diatonic nooks and crannies of the major scale / major tonality. Go to diminished color / major tonality for a look at more passing chord options using root position diminished chords.

Jazz trick. Wait to sound the diminished color to the 3 beat of measure 2 to streamline the anticipation, especially in the brighter tempos. For shedding, once the color is under the fingers, just decrease the size of the diminished window in the music so to speak and dig the wee extra squeeze of coolness out of the diminished tension.

Do we ever use inversions of the diminished chord color? For sure, although how much of the diminished chords timbre is affected by the different inversions is pretty subjective to one's own way of hearing things. Either way, perhaps similar sounds, but for sure a different bassline. Example 3c.

Same sound? No surprise eh? The diminished color is very distinct. What part does the bass line have in affecting the storyline of a song? Do you think we could get a sense of a song's character by simply playing just the roots of the written chords? Clarke Terry thinks so. Perhaps try this approach the next time you begin to learn a new tune? See if the "storyline" emerges from the "sounding of the roots." 

In regard to tonal destinations, viewing the pitches of the fully diminished seventh chord as leading tones creates some interesting possibilities and potentials. Four different leading tones in one chord? Perhaps needless to say that this diminished color is quite unstable, potentially being pulled in four different directions simultaneously? How can we use this to our best advantage? Well, let's look at the theory of these leading tones and see. Here is a chart extracting the four diminished chord pitches from the examples above, viewing each as a leading tone and pairing them with tonal centers. Example 3d.

Minor keys as well? Yes indeed.

One key principle of these possible resolutions from both a theoretical and aural sense is that "if we lower any one pitch of the fully diminished seventh chord by half step, we create a vanilla dominant seventh chord." Let's chart out the possibilities. Example 3e.

Cool with this? Potentially a big step for the emerging theorist. Why? Well, based on the multiple key resolving properties of the fully diminished seventh chord, we can soften the diminished color into dominant seventh chords, then mix and match these colors as our creative muse dictates and resolve to different tonal destinations. Is this where our basic principles of dominant chord substitution come from? Exactly. Is it the only way? Of course not, but the theory contained within the chart of example 3e is a solid place to start. Thinking C major, here are the four dominant seventh chords from the chart above resolving to a common tonic. We start with the most common diatonic motion and gradually move outside. Example 3f.

Measure 34 above is the common diatonic dominant ( V 7 ) to tonic ( I ) motion. The cadential motion in measure 35 uses the b 7 substitution so common in blues and the Latin stylings. Bar 36 is the cool tritone substitution, so named because of the root relationship between the roots of the diatonic dominant G and the substitution chord Db. This tritone sub is often times located on the "bread and butter" section of a jazz players palette and is a bebop and "standards" essential substitution. In measure 37, the major third to tonic motion is perhaps the more "modern" sounding of the four possibilities and oftentimes is used in the more polytonal colored musical environments. Cool with this? Depending on too many factors to list and consider in regards to one's musical directions, the above cadential motions and the possibilities they imply could potentially make one's musical universe go kaboom in so many positive ways.

What's next? How about exploring various diminished chord colorings by chord type?

So where can we employ the fully diminished seventh chord and it's multiple resolving possibilities? How about...

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