• Did You Know The Diminished Seventh Chord Has Two Mutual Tritones?

    in Chords & Progressions,Piano,Theory

    In this lesson, we’re projecting the diminished seventh chord as two mutual tritones.

    This is another perspective to the diminished seventh chord that would deepen your understanding of the chord – trust me!

    However, before we get into all that, permit me to start by doing a quick review on the tritone.

    A Review On The Tritone

    In a previous post, we began our discussion on the tritone. The tritone is a distance of three adjacent whole steps (aka – “whole tones”.)

    History Of The Tritone

    The tritone, which is one of the first harsh intervals to be discovered was labelled diabolus in musica which means ‘the devil in music’ in Latin.

    So many centuries ago, when master musicians were church men, neither the devil nor his interval was welcome in church, therefore the tritone was not used so much until the nineteenth century.

    Musicians of the nineteenth century believed in the ghostly, nocturnal, and the fearful. They implored and explored the sound of the devil in music.

    Formation Of The Tritone

    Here’s the tritone formed on C…

    From C:

    …the first whole step is D:

    From D:

    …the second whole step is E:

    From E:

    …the third whole step is F#:

    …(aka – “Gb”):

    Spelling Of The Tritone

    Due to the fact that F#:

    …and Gb:

    …are enharmonically related, a tritone can either be C and F#:

    …or C and Gb:

    Now depending on your spelling of the tritone, it can either be a diminished fifth or an augmented fourth.

    A diminished fifth in the case of C and Gb:

    …or an augmented fourth in the case of C and F#:

    So you need to learn how to spell intervals correctly if you are still finding it challenging to understand why the tritone can either be a diminished fifth and augmented fourth.

    Melodic/Harmonic Outcome Of The Tritone

    According to Jermaine Griggs, an interval is the relationship between two notes in terms of the distance between them.

    When an interval is played or heard one after the other (melodically) or at the same time (harmonically) the combination can either sound pleasant (consonant) or unpleasant (dissonant.)

    The tritone when played or heard, produces an unpleasant combination (aka – “dissonance”) because it is an augmented fourth or diminished fifth and all augmented and diminished intervals are dissonant and were forbidden several centuries ago.

    Tritonic Chords

    Music scholars classify chords that contain the tritone as tritonic chords.

    All tritonic chords produce an unpleasant combination of notes (aka – “discord”) because of the inherent dissonance in the tritone.

    The minor sixth, dominant seventh, half-diminished, and diminished seventh chords are examples of tritonic chords and are considered to be harmonically unstable because when they are played, they have the tendency to resolve to a stable chord.

    The Diminished Seventh Chord

    Let’s get further into today’s lesson by taking a closer look at the diminished seventh chord. For those who would want to know more about the diminished seventh chord, I’ll want to start with a review of the diminished seventh chord.

    “What Is The Diminished Seventh Chord?”

    The diminished seventh chord is the seventh degree chord of the minor key. You can form the diminished seventh chord on the seventh degree of the melodic and harmonic minor scales.

    In the A harmonic minor scale:

    …where G#:

    …is its seventh degree, you can form the G# diminished seventh chord by stacking notes in thirds until seven scale steps are encompassed. Check it out…

    A third from G# is B:

    A third from G#-B is D:

    A third from G#-B-D is F:

    Altogether, we’ve formed the G# diminished seventh chord:

    …by encompassing seventh scale notes in thirds.

    Let’s quickly transpose the diminished seventh chord to all twelve keys…

    C diminished seventh chord:

    C# diminished seventh chord:

    D diminished seventh chord:

    D# diminished seventh chord:

    E diminished seventh chord:

    F diminished seventh chord:

    F# diminished seventh chord:

    G diminished seventh chord:

    G# diminished seventh chord:

    A diminished seventh chord:

    A# diminished seventh chord:

    B diminished seventh chord:

    Submission: I spelled the F diminished seventh chord as F-Ab-Cb-D, instead of F-Ab-Cb-Ebb because my chord share tool doesn’t spell double sharps and double flats yet. Please take note of the appropriate spelling which is F-Ab-Cb-Ebb. I also did an enharmonic spelling of the C diminished seventh chord.

    Intervallic Breakdown Of The Diminished Seventh Chord Into Mutual Tritones

    The diminished seventh chord can be broken into two intervallic constituents, and these intervallic constituents are tritones.

    Take a look…

    Here are the intervallic constituents of the G# diminished seventh chord:

    G# and D:

    …a tritone.

    B and F:

    …another tritone.

    From the breakdown of the G# diminished seventh chord above, you can see that it contains two [mutual] tritones, and this gives us another perspective to it.

    Chord Formation Of Diminished Seventh Chords Using Mutual Tritones

    The formation of the diminished seventh chord just got easier now that you know that it has two mutual tritones.

    However, to do this formation, you must be familiar with the tritone in all twelve keys. Here is the tritone in all twelve keys…

    C tritone:

    C# tritone:

    D tritone:

    Eb tritone:

    E tritone:

    F tritone:

    Gb tritone:

    G tritone:

    Ab tritone:

    A tritone:

    Bb tritone:

    B tritone:

    Using the tritones above, you can form the diminished seventh chord by stacking two tritones that are three half steps apart from each other.

    “Let me show you step-by-step how this is done…”

    To form the A diminished seventh chord, you’d need two mutual tritones – one on A:

    …and another one that is three half steps above A. Three half steps above A:

    …is C:

    Therefore a tritone built on A:

    …and another one on C:

    …if put together, forms the A diminished seventh chord:

    “Let’s take one more example and we’re done…”

    To form the E diminished seventh chord, you’d need two mutual tritones on E:

    …and one another note that is three half steps above E. Three half steps above E:

    …is G:

    Therefore a tritone built on E:

    …and another on G:

    …if put together, forms the E diminished seventh chord:

    Every other diminished seventh chord can be formed on the keyboard following the same procedure.

    Final Words

    Chords that have the tritone as an intervallic constituent are said to be tritonic.

    The diminished seventh chord is the only chord in music that has two tritones and as such, is considered to be extremely harsh.

    Tritonic chords because of their  inherent discord tend to resolve to stable chords – major seventh chords, minor seventh chords, etc., and the diminished seventh chord is not an exception.

    The diminished seventh chord because of the two mutual tritones it contains, has a stronger affinity for [and tendency to resolve to] major and minor chords.

    Suggested Reading: A Study On The Leading Note Chord [Of The Seventh Degree.]

    Thanks for your time.


    What are the two mutual tritones that the diminished seventh chord below:

    …can be broken down into?

    Kindly post your answers in the comment box below.

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    Onyemachi "Onye" Chuku is a Nigerian musicologist, pianist, and author. Inspired by his role model (Jermaine Griggs) who has become his mentor, what he started off as teaching musicians in his Aba-Nigeria neighborhood in April 2005 eventually morphed into an international career that has helped hundreds of thousands of musicians all around the world. Onye lives in Dubai and is currently the Head of Education at HearandPlay Music Group and the music consultant of the Gospel Music Training Center, all in California, USA.

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