The Fully Diminished 7th Chord

This chord is incredibly important to come to grips with, for understanding Music Theory as a whole. Let's take a quick look.

Below is a way to play the chord with the root on the E, A, or D strings. Try it out now!

That's a double-flatted 7th by the way, AKA, a Diminished 7th. It's equivalent to a Major 6th. A little strange, I know.

Diatonically, this chord does appear when building a chord off of the 7th Scale Degree of the Harmonic Minor.  But you'll see it used in many other places than that. There's all sorts of non-diatonic uses for this chord.

Now, the easiest way to play the chord jumbles up the order of the notes, moving the b3 up to the top of the shape. But, if you play the intervals in order, (1 - b3 - b5 - bb7), you might notice a pattern emerge.

Each note of the chord is a Minor 3rd above the previous! The symmetry of this chord makes the tonal center quite ambiguous.

In practice, this means that we can treat any of the 4 notes like the root of the chord, and it'll work just fine.

Diminished Chords are a bit of a rabbit hole, there's just so many interesting uses for them. You'll find that despite the tense sound, they're almost like duct tape for a chord progression.

If you're interested to learn more, please follow the link to learn about Understanding Diminished Chords.

See you there!