The half-whole scale is perhaps one of my favourite scales for a few reasons.

• It has so many different intervals crammed into it that it can be played over pretty much anything
• It repeats itself every minor third so is very easy to improvise with
• Its symmetry also makes it easy to play the same scale in other keys

Scale Structure

The half-whole scale is structured like so:

C  Db  Eb  E  Gb  G  A  Bb
1  b2  b3  3  #4  5  6  b7

Symmetrical Properties

Like I quickly touched upon in the bullet points, the half-whole scale is a symmetrical scale. It is not symmetrical in the strict sense that it divides the octave up into equal parts like a whole-tone or chromatic scale would, but the sequence of notes in the half-whole scale is symmetrical.

For example, in our above table, if we isolate the first three elements of the scale (C, Db, Eb) and view their intervals, we get the formula:

1  b2  b3

If we move up a minor third to our Eb and look at the interval sequence (Eb, E, Gb) we get:

1  b2  b3

Because of this symmetry, any pattern and any chord you play can be played a minor third up or down, lending itself well to some weird modulations and to very easy improvisation.

That means that you can play some random noodles in the half-whole scale and move that whole noodle up a minor third and it will still work just fine. This works with chord sequences too!

Let’s take a nice relative minor/major chord jam over a I - VI progression in C.

We’d play

C - Am

Remember that all the notes of both these chords are in the scale. We can then move this I - VI sequence up a minor third:

Eb - Cm

And it is still completely legal and within the scale!

All the notes of these chords are also in the scale. Let’s move it up one more minor chord to be sure:

Gb - Ebm

Yep! Still works. If you’re still not getting this, let me say it.

ANY GENERAL SEQUENCE WILL WORK IN MINOR THIRDS!

With our new found knowledge of the half-whole scale and its undeniably amazing symmetry, let’s look at ways to apply this.

Improvisation

Every time you look at a scale’s formula, you should immediately try and think what it works well over. So, what does this scale work well with? Well, quite a lot.

Let’s start by saying this, the half-whole scale is a WEIRD scale, if you’re trying to go for a nice pop solo, good luck and may god have mercy on your soul.

With that out the way, let’s begin the analysis.

It works well over a minor backing.

This scale has all of the suitable requirements to work over the Dorian mode. It has the minor 7 arpeggio intervals (1, b3, 5, b7) and it also has the natural 6. Want an outside dorian-esque sound? The half-whole comes to the rescue!

Not only that but it can stretch a bit further than that. The b2 allows us to improvise freely over the phrygian mode without any qualms. As long as you be careful about your note choice, you can improvise in all minor modes (even locrian!)

It works well over a dominant backing.

Again, this scale has all the necessary requirements. The major third, perfect fifth and flat seven work well over a dominant setting. Try using this in-place of where you would usually insert your mixolydian goodness!

It also has some melodic-minor sweetness in it as well. This scale supports the lydian dominant scale very well. If you look at the main chord tones of a lydian dominant chord…

Lydian Dominant
 1 3 #4 b7

You can see, the half-whole scale fully supports it.

Aside from that, our scale has all altered tones apart from the #5, so feel free to throw this over altered dominant chord tones too!

Lastly

It works well over diminished chords.

It has all necessary chord tones of a diminished chord so you can pretty much go crazy with it. And, due to its symmetrical nature, you can just repeat the same pattern a minor third up, you’ll sound clever and know what you’re doing even though it’s actually easier than doing anything else!

More improvisation

I’ve just touched upon some of the more ‘usual’ uses of this scale, so let’s explore the more unusual. In this case, the more unusual is actually the more conventional (god dammit, why does everything have to be so hard to understand!)

Well, when you play a weird chord sequence that belongs to a weird mode such as lydian dominant, people will usually expect you to play some outside notes and some altered tones. If we reverse this the same is true, when we play a ‘vanilla’ chord sequence such as a major I-IV-V. People will probably expect you to just play the major scale throughout, this is where I believe the half-whole scale comes into a realm of its own.

If you’re going for an outside sound and are careful about your note choice, there is no reason why you can’t play the half-whole scale over a happy major backing.

The scale has the 1st 3rd and 5th intervals so it technically can possess a major tonality, just BE CAREUL. For the love of god, there is a minor third right next to that major third!

The same can be said for the minor scale since the half-whole also possesses the b3rd.

having touched upon improvisation, let’s move onto backing/harmony and more!

Harmony

Welcome back to how to play absolutely anything over absolutely everything.

Now we’ll begin investigating harmony and modulation, I find the half-whole a great scale a great scale to pivot into, it takes you to some strange places.

First, before we do anything, we’re going to construct some 7th chords from every interval of the half-whole just to get a feel of what we can do with it. I won’t be constructing these by traditional means as the chords will be downright unusable. Instead I’ll try and derive the most common 7ths I can from the scale so that it’s easy on our western brains.

Half-Whole 7th Chords

C7
1 3 5 b7

Cm7
 1 b3 5 b7 
 
Db diminished
  1  b3  b5  bb7

Remember what we said earlier, everything can be repeated a minor third up, that means that the above 3 chords are pretty much the basis for our harmony. There are many other chords you can form with the half-whole (being octatonic, you can pretty much stretch the scale how you would like)

So, let’s begin our look at how to modulate into the half-whole, stay in the half-whole for a while and then come back to reality.

Looking at the above table, we can see a 7chord. 7chords are a very good pivot tone due to the amount of directions it can go (read this article to find out why). If we take the C7 and work out all 7 chords separated a minor third, we get the following list.

C7 - Eb7 - Gb7 - A7 - C7

Likewise with the other chords;

Cm7 - Ebm7 - Gbm7 - Am7 - Cm7

Db dim - E dim - G dim - Bb dim - Db dim

So that’s our whole table populated!

For simplicity, we’re going to be playing in F. I’ve chosen F because its V chord is the C7 and so we can go from that C7 into all other half-whole oddities.

To make things easier, we’ll construct a table showing all the common chords between the half-whole scale and the F major scale, doing so will make modulation easier as we can pick out our pivot chords without much thought. This takes time, but it saves us time in the long run. (Note that in the table I’ve also used D harmonic minor (relative minor of F) to allow us a bit more flexibility with the chords that we can modulate to).

Common chords of F and Half-whole

C7
C E G Bb
 
Am7
A C E G
 
A7
A C# E G
 
E dim
E G Bb Db

We’ll play a simple jazz sequence which will then pivot into the half-whole. Our jazz sequence will be the classic I - vi - ii - V in F major;

F  Dm  Gm  C7
I  vi  ii  V

For the sake of being succinct, I will modulate quickly and harshly to the half-whole. Normally, you’d set up the modulation a bit better so that you can give the song room to breathe before all guns go blazing and you’re modulating to distant keys.

Here’s our full sequence.

 F   Dm   Gm   C7  F   Dm   A7     C7  Eb     C   Eb     C7
 I   vi   ii   V   I   vi   III7   V   bVII   V   bVII   V

It’s only a brief modulation towards the end (where it goes to eb). Admittedly I’m not the best at roman numeral notation so my ‘III7’ may not be seen as ideal.

Sadly, our time must come to an end, I’ve got one last little treat that I recorded a few years ago (I knew it’d be relevant one day!). It’s a short video demonstrating the half-whole scale.

Watch here