This one’s for Elton Mottley, a guitarist (and southpaw, unless he’s flipped his avatar). He recently got in touch to say he didn’t know what a hexatonic was. No shame in that at all.
I have a somewhat childish streak to my sense of humour (you might have noticed) and replied to Elton that a hexatonic is what witches drink when they’ve run out of gin. But I also said I’d post something about hex scales, so here it is, just in time for Halloween.
A hexatonic scale, in the simplest terms, is a scale with six tones. Oh wow, thanks for that, wish I hadn’t bothered. But bear with me – there are ways of deriving them, thinking about them and playing them that can bring a lot of wonderful, interesting structure to what we do as improvisors and composers.
TOM AND STRAVINSKY
Here’s a snippet from the piano reduction of Petrushka (Act II):
If your reading or ears aren’t brilliant, don’t worry – just bring to mind the signature motif you hear when Jerry peeks out of his mouse hole in the skirting board (usually followed by some Mickey Moused blinking – doink doink doink).
Classic cartoons used a fabulous portmanteau of music from classical orchestral to big band and even the avant garde. What a joy it must have been to take part in those frantic manic sessions, with a huge ensemble arranged, conducted and edited so as to make a meticulously planned “hit” every few seconds… And what a perfect job – being the “doinker” player for the MGM orchestra!
But what exactly is this, from a musical perspective? As so often in life, this great act of imagination is really just inspired use of simplicity. The two parts are major triads, they’re just a tritone apart (F# in the LH, C in the RH). It’s a wonderful, evocative, distinctive sound, but for all that it’s modernistic it’s really just two of the simplest gestures imaginable put together. And it’s such a common sound nowadays that it’s easy to overlook how strikingly original and otherworldly it must have seemed at the time.
The “Petrushka chord” introduces the age-old magical, slightly creepy, notion of a puppet being alive… The ballet continually plays with the idea of who and what we are supposed to believe is “real”, and Stravinsky’s pioneering theme plays to that charming, discomforting uncertainty.
Now what old Igor is doing here is generally described as bitonality, ie two different tonalities coexisting. There’s a simple principle in music – the weirder you get, the more structure you use, otherwise the ear has nothing to latch on to and it just sounds like random noise. (Of course, some modern composers seem to think our ears are as clever as the composers think they themselves are, but that’s a whole different rant…)
What if we were to lay out the notes Stravinsky uses sequentially, as a scale?
C C# E F# G A#
You might recognise this as the half-step whole-step diminished scale – what we’d play over C7b9 – with a couple of notes missing. And that’s a very handy use for it. To play over any 7b9 chord take the home major triad and combine it with the major triad a tritone (#4th) away – as a chord, an arpeggio or woven together as a scale, it’s up to you. (We can also use the minor triads, but let’s not get ahead of ourselves just yet.)
THERE’S MORE, SO MUCH MORE…
One of the most useful ways of deriving a hexatonic scale is to take two mutually exclusive triads and combine them, overlay them. You can take any triads of any quality you like and experiment with them (the possibilities are many, and some are weirder than others). As we saw, Stravinsky took C and F#, but here’s a more generalised notion for practical usage in jazz improvisation. We can adapt his approach to work within chord sounds as well as evoking magical marionettes.
Consider the simple major triads built on the roots of the whole-tone scale:
C D E F# Ab Bb
Now combine the triads in pairs as you go up:
- C and D triads used together give a C#4 (Lydian) sound. You’re not playing the 7th, so it could be either a major or dominant.
- D and E give a CM#5 (Augmented) sound.
- F# and Ab give a C7#9 (Altered) sound.
- Bb and C again give a C7sus9 sound.
That’s just thinking of them as C chords. Now go through them again and think of all the other chord types that those combinations of notes would fit – eg C and D together fit Am7 (and many others, including eg BbM#5); Bb and C fit Gm7; F# and Ab together fit any chord from Db melodic minor; and so on. That’s just a few for starters, and we haven’t even considered the possibilities of throwing together minor, diminished or augmented triads, or even combining chords extended beyond the triad…
Incidentally, if you’re into writing things out and reading, I find the following kind of notation can be visually useful, whether on practice charts or arrangements:
On chord charts, what we’re dealing with here is polychords, which shouldn’t be confused with slash chords. (In fact a discussion like this of hexatonic scales is really just an introduction to the subject of polychords). You’d notate the above as:
Bb/Ab (which musicians will interpret as a Bb chord over an Ab bass note).
Anyway, the beauty of using gapped scales derived from structures is that they are simultaneously distinctive and ambiguous. Embracing ambiguity is absolutely crucial with gapped scales – it’s unavoidable and also part of the charm.
Don’t think “Oh, I can’t play that – it doesn’t even have a 3rd or a root”. Don’t worry about what’s missing, think of what that group of notes would fit over.
The trick when improvising or composing with hexatonics is to artfully disguise the fact that all you’re doing is interweaving two of the simplest musical gestures to make a more interesting whole. The really cute thing about this approach is that it’s so accessible – triads are among the first things we learn as kids. in fact, aspiring jazzers spend years trying to get beyond the tame sound of triads. But use two of them together and you’re immediately into all sorts of wonderful sounds, often very far from tame.
Mwahahahaaaa! It’s witchcraft… wicked witchcraft… It’s a trick and a treat.
See also Sussing Out the Blues