If you recall from our lesson on diminished triads, we are working with a series of minor thirds. When we relate these notes to the major scale we say that we are working with the root, ♭3rd and ♭5th. If our root note is G, then we’re working with G, B♭ and D♭.
If we extend the idea of using a series of minor thirds and add another one beyond the flat fifth we get what music theory types call the ♭♭7. If G is our root, that note is an E, which happens to be a minor third below G. Which means that four consecutive minor thirds in a row neatly divide an octave into four intervals.
Now you’re probably scratching your head over this “♭♭7” nonsense. Let me try to explain it. Music theory types by and large like a neat and orderly world. As we’ll see when we build up more complicated chords, the chord-naming theory is all based on building chords from some combination of minor and major thirds (for now, just go with me on this).
Building an arpeggio (or a chord for that matter) up entirely from minor thirds seems to make a lot of sense. As I said earlier, we build chords from minor and major thirds. But the actual notes don’t quite line up the way we like. If we add a minor third to a diminished (flat) 5th we get a note that matches the major sixth of the scale.
Uh oh. That confuses things. So the solution is to instead call that note a ♭♭7th. It may sound ridiculous and borderline obsessive-compulsive, but it keeps our nice little world of music theory neat. If you’re not a neat-freak, don’t get too hung up on this. Just go with it.
Okay, enough talk. Let’s play something. Here’s a series G diminished arpeggio forms starting at the first position:
All we are doing is playing one minor third after another which results in a real artifical, robotic kind of sound. In music theory terms we say that the diminished arpeggio (or chord or scale) is atonal because it doesn’t have a tonal center that our ear wants to resolve to. The diminished arpeggio (and chord and scale) just seems to “float” out there with no resolution.
As we move up the neck, here’s the next pattern you can play:
Alright, nothing too magical there. But now take a look at what happens as we move up the neck:
That arpeggio shape is exactly the same as the first shape. Does this seem familiar? We saw the same idea when we looked at augmented arpeggios.
If we keep moving up the neck, sure enough, we get a repeat of the second pattern:
The diminished arpeggio, like its augmented counterpart, is built up from equidistant intervals. Each note in the arpeggio neatly divides the octave up into the same intervals. The augmented arpeggio splits the octave into three major thirds, the diminished into the four minor thirds.
This means that you can pick any of the four notes in your diminished arpeggio and call it the root. It also means that a single diminished chord shape (or arpeggio) is actually four chords in one! A G diminished is also a B♭ diminished is also a D♭ diminished is also an E diminished.
Like the augmented arpeggio, you may find that it’s easier to simply think in terms of stacking minor thirds than to memorize individual shapes. Do whatever works best for you.
The diminished sound is most often heard in jazz. It’s often used as a setup to resolve to a more stable chord, like this:
Try just playing the first two chords and then stop. Weird, right? You’re just left hanging. That’s the tension that the diminished sound brings to the table. Our ears really want to hear the third and fourth chords in order to make the whole progression resolve. Tension and resolution. Tension and resolution. It’s easily one of the most important things in music.
Now the jazz guys haven’t cornered the market on the diminished sound (though they use it the most). A lot of country guys like Brad Paisley will toss the odd diminished lick in every so often just to make sure you’re paying attention. Rock guys will do the same.
Here’s an example of jamming a diminished arpeggio into an otherwise straight-ahead blues shuffle groove:
The lick looks like this:
The diminished bits happen in the first and third measures of this lick. The key here is to just outline the diminished tonality enough to make it interesting without overstaying your welcome. Otherwise the rest of the lick stays firmly planted in a bluesy G kind of sound.
With these basic arpeggios under your belt, we can now start to look at more sophisticated chords and arpeggios. In our next lesson we’ll start looking at “seventh chords”. We’ll figure out how they sound, what they look like on the neck and why we give ’em that name.
Until next time, keep rocking!