The diminished scale is one of the most useful and versatile tools for jazz improvisers. It has been covered on LJS before, but I want to try to offer an additional perspective on how to think about and use this scale.
You might already know about the diminished scale, but a lot of jazz musicians are familiar with the diminished sound and yet do not tap into the full potential of this unique scale. Likewise, you might already know how to play a diminished scale – but where do these scales come from, how are they theoretically derived, and what are their unique properties?
In this post, I’m going to walk you through some basic answers to these questions and talk about the most effective ways to incorporate the diminished scale into your playing.
What’s the history of the diminished scale?
Diminished-like scales and other symmetric scales have been used in non-Western music for centuries (and perhaps even millennia). There a few freak incidences of diminished scales in earlier periods of European “classical” music history, but diminished scales began to appear more definitively as a distinct musical idea in Western music during the so-called “Romantic Era” in the 19th century, especially in the music of Russian composer Nikolai Rimsky-Korsakov and his students/imitators.
By the early 1900s, the idea of the diminished scale began to be formally theorized and codified. During the first half the 20th century, composers such as Bela Bartok and Igor Stravinsky began to make extensive use of the diminished scale in their compositions. In jazz history, definitely by the time bebop emerged, many improvisers were aware of and using the diminished scale.
What is a diminished scale and how are diminished scales derived?
The diminished scale is a special scale that accompanies a fully diminished 7th chord. Just to review, a diminished 7th chord is constructed by stacking minor thirds on top of each other until you build a 7th chord. Here’s a diminished 7th chord:
There are 3 ways to think about constructing the scale that corresponds to the diminished chord:
1. Combine two minor tetrachords a tritone apart (a tetrachord is a 4-note scale, and a minor tetrachord is basically the first 4 notes of the Dorian minor mode, so for example, combine the first 4 notes of a C- scale with the first 4 notes of an F#- scale)
2. Play alternating whole- and half-steps:
3. Combine two fully diminished 7th chords a whole step apart, for example, combine C(dim.)7 and D(dim.)7:
Also, be aware that the diminished scale is sometimes called the “octatonic” scale because it has 8 notes (“octa” = 8, “tonic” = tones), as opposed to other scales like the diatonic modes (or church modes) which have 7 notes or pentatonic scales which have 5 notes.
What are the unique properties of the diminished scale?
Diminished scales are symmetrical scales, meaning that they can only be transposed into another “key” a limited number of times before they repeat themselves – before you get the same scale with the exact same pitches, just starting on a different note. Since they are “limited transposition” scales, you can’t generate modes from diminished scales the same way you can with an asymmetric scale, such as the major scale (also called the Ionian mode).
As it turns out, there are only 3 diminished scales. If you don’t believe me, try building diminished scales yourself and see how many unique scales you can generate before you wind up with a scale with the exact same pitches as the one you started on, just played in a different order.
Diminished scales have a lot of built-in major triads and 7th chords.
Using only notes derived from a given diminished scale, you can extract a lot of useful and familiar-sounding harmonic structures. This is useful – one of the best ways to tap into the “diminished sound” is to play melodic patterns based on the internal structures of the diminished scale, as opposed to just running up and down the scale in stepwise motion.
There are major triads, dominant 7th chords, dominant 7th (b5) chords, minor 7th chords, and minor 7th (b5) chords you can build off of the 2nd, 4th, 6th, and 8th scale degrees of the diminished scale. There are also fully diminished 7th chords you can build off every note of the diminished scale, and there are diminished major 7th chords you can build of the 1st, 3rd, 5th, and 7th scale degrees. Here’s a visualization to show what I mean:
There are a few other types 7th chords you can extract from the diminished scale – see if you can find them for yourself: diminished major 7th, minor (major 7) b5, major 7 (sus 4) #5, and major 7 (sus 4) b5.
How do you use diminished scales?
Here are some of the best applications of the diminished scale:
1. Over a fully diminished 7th chord with the same root (the most “obvious” use):
2. Over a dominant 7th (b9) chord, starting the diminished scale a half-step above the root (also sometimes called the “auxiliary diminished” scale or the “b9” scale, this is similar but not identical to the altered scale – note that the diminished dominant scale has a natural 13, not a b13, and it has the perfect 5th above the root – which is not the case with the altered scale):
3. Over a minor II-V7 with the diminished scale starting on the root of the II-7(b5) chord (resolving to the diatonic Dorian mode on the I- chord) – note that one diminished scale works nicely over both the II-7(b5) and the V7(b9) chords:
4. Over a pedal point (any diminished scale will work, but most often the chord with the same root as the pedal note works best):
Finally, here is a very useful “insider” tip: diminished scales work best starting with the whole step first when playing both ascending or descending step-wise melodies over dominant 7th (b9) chords. This is because it allows the chord tones and the “colorful” notes to fall on the beat when using the diminished scale over dominant 7th (b9) chords. Most importantly, it also makes resolving into the next chord generally easier and more natural. For example:
I hope you find this a helpful guide for exploring diminished scales. Be aware that there a number of exotic sounding melodic patterns you can create from the diminished scale because it is symmetric – see if you can come up with your own patterns, and happy practicing!