The Half-Whole Diminished Scale
In my last scale lesson, we examined the aptly titled Altered scale and hopefully you found that it is very useful for playing over altered dominant chords.
As a quick reminder, Altered dominant chords are 7th chord structures which features tones drawn from outside of the parent key/scale. V7 chords are often altered in this way in a typical II V I progression.
Another popular scale for these altered dominant 7th chords is the subject of this lesson and it’s called the H/W diminished scale.
The H/W stands for ‘half-whole’ and describes the order of intervals that the scale begins with (a half step to whole step or if you prefer, semitone to tone) The H/W diminished is a symmetrical scale form and as a result can give rather an angular or even mathematical sound when used for soloing.
Let’s first examine the scale’s construction and then some common applications.
As you will see from the music above, this series of pitches is actually quite similar to the altered scale, but with a couple of significant differences.
The first of these is the fact that the scale is comprised of eight separate notes, rather than seven and it maintains a symmetrical note order throughout. If you examine the interval distances between each note, you will see that it alternates between half-steps and whole-steps (semitones to tones) hence the name.
Here are some fingerings that will help you get this symmetrical sound into your playing vocabulary and as I mentioned with the altered scale, try to work on these in a predetermined area of the fingerboard and begin by ascending the C Major scale for example and then descending the G H/W diminished.
For improvisational purposes, this diminished scale is commonly employed over altered dominant chords where there is a b9, #11, and 13 present (either singly or in combination) and if you go back to my last lesson on the Altered scale you can try the scale out with the backing tracks I posted there.
Another useful approach that you can take with the H/W diminished scale is to play triads built from the scale. A common approach is to build major triads (you can also use minor triads from the same root notes) from the root, #9, b5 and 13th. In this case, that would yield a G, Bb, Db and E major triad. This concept produces some very modern intervallic sounds and here are some examples to get you going: