The Augmented Hexatonic System

In a previous post I made some observations about what I call the Augmented Hexatonic (1 b2 3 4 #5 6). Here I pull some harmony out of the resulting scales. You should probably read the earlier post before getting into this one.

Augmented Hexatonic is a symmetrical scale with two modes, both of which have a "major seventh" kind of flavour. One is 1 b2 3 4 #5 6, which is a close relative of Double Harmonic (1 b2 3 4 5 b6 7). I tend to think of the latter as a pair of Maj7 arpeggios, one at the root and one a semitone above it. The former is just the one above the root along with a couple of extra notes (3 and 6) that suggest a Maj6 chord.

The other mode is 1 #2 3 5 b6 7, which you can think of as a Maj7 arpeggio at the root plus another Maj7 arpeggio at the 3 or the b6. In fact I tend to "see" all three of these arpeggios imposed together as a little grouping. Their roots form an augmented triad and they're the three tonic chords of the famous jazz tune "Giant Steps".

As a consequence I think of this as the "basic version" of Augmented Hexatonic and the other mode as the "fancy version". College jazz textbooks will tell you that IVMaj7, which is in the fancy version, isn't a wise substitute for IMaj7, and that means the result is guaranteed to be interesting. It also contains the b2, a favourite sound of mine on a Maj7 chords.

[NOTE: It's been brought to my attention that I made a booboo in the previous post. What I was calling Gayakapriya there is in fact a mode of Gayakapriya that I call Vanaspati b5. I'm going to double down and continue referring to "Gayakapriya" here, mostly because I forgot and made all the diagrams with that name, but also because the notion of a root note is pretty fluid in my playing these days and I don't make a big fuss about different modes if they belong to the same scale group. If this was a book or something else more proper I'd fix it but these posts are more in the way of journal entries, so I'll let the error stand.]

As my previous post explains, Neetimati and Gayakapriya are the unique scales (ignoring modality) that can be made by adding one note to the Augmented Hexatonic. Here are some basic chord grips of the kind I play a lot, moved up through both scales. The added note is A throughout this post -- as usual choose any set of strings and follow the colours:

The Augmented Hexatonic can be thought of as a pair of augmented triads, so of course we can get these scales from those too. Here Gayakapriya is first, then Neetimati:

As I mentioned above, Augmented Hexatonic can also be thought of as three overlapping Maj7 chords separated by major thirds. Finding these is easy. From the root, go either up or down a whole tone to make Gayakapriya, or go down a semitone or up a minor third to make Neetimati. I use these a surprising amount and even as bare triads they can sound very striking.

Augmented Hexatonic can also be thought of as two disjoint copies of 3-4, one in each inversion. So these are also found in Neetimati and Gayakapriya -- here the yellow notes are one inversion (1-3-4) and the green are the other (1-5-b6):

(There's one mistake in the diagram -- D string 10th fret should be green. Sorry, I can't be bothered to recreate it just to fix that one note...)

Remember from the previous post that in both cases the coscale -- the notes not in the scale -- is b2 3 4 #5 6, which is just the normal Augmented Hexatonic with the root left out. Obviously, you can expand that into either Neetimati or Gayakapriya, providing four possibilities over an A root note:

  • A Gayakapriya + Bb Neetimati
  • A Gayakapriya + G Gayakapriya
  • A Neetimati + G# Gayakapriya
  • A Neetimati + B Neetimati

These relationships are easier to see on the instrument than they are to squint at on-screen, but it may help to notice that when combining both scales their roots are a whole tone apart but when combining two copies of the same scale they're only a tone apart.