The Tritone Scale

Many years ago, when I first became aware of chord superimposition, I hit upon a unique concept. Inspired by my new awareness of tritone substitution, I thought, What would happen if I took two major triads a diminished fifth apart–C and F#, for example–and crunched all the notes together to form a scale? Wouldn’t that be cool!

Of course it had already been done, just not by me. My musical innovations tend to be in the same league as my discovering fire, gravity, the wheel, Chicken McNuggets, things like that. In this case, I had stumbled upon the tritone scale, so named for obvious reasons.

tritone-scale
Think of a diminished scale with two notes missing, kind of like a smile with a couple teeth knocked out, and you have the tritone scale. The standard C half/whole-step diminished scale consists of the notes C, Db, D#, E, F#, G, A, Bb, C. If you remove the notes D# and A, the result–as shown in the first example (click to enlarge)– is a C tritone scale: C, Db, E, F#, G, Bb, C.

The tritone scale falls in the class of scales called hexatonic (six-tone), which also includes the augmented, whole tone, and blues scales. Since the tritone scale is derived from two major triads, you’ll of course find those triads contained in it. You’ll also find two dominant seventh chords native to the tritone scale. (See second and third examples.)

The leap of a minor third between the second and third tones, and between the fifth and sixth tones, renders the tritone scale asymmetrical. That asymmetry lends color to the scale and makes it a good source of angularity. By its nature, the tritone scale will make you think a bit differently than you would if you were using a complete diminished scale–with which, I should add, the tritone scale is interchangeable.

The last two examples in the image are actually exercises on the tritone scale. The first is a straightforward scale exercise. The second alternates the two triads that are native to the scale, taking you through their different inversions. As always, play each exercise through the full range of your instrument.

How to use the tritone scale in improvisation

All that theory is fine, but what about actual application? Naturally you want to know how the tritone scale is used.

Use it anywhere you would use a whole/half-step diminished scale. The most obvious use is with a V7b9 chord. Since, as I’ve said, the tritone scale is interchangeable with the diminished scale, you can use it with any of four different dominant chords. For instance, you can use the C tritone scale with C7b9, Eb7b9, F#7b9, and A7b9. Note that two of these chords, the Eb7b9 and A7b9, are built upon the “missing notes,” which means you can skate around the chord roots without ever landing on them.

Tritone scales built on the roots of dominant chords pack the advantage of having the tritone substitution built right into them. The second exercise (last example) demonstrates this beautifully and is one you definitely should get under your fingers.

The tritone scale also adds interest to minor scales. Use the seventh of the scale as the chord root. Another way of thinking of it is, use the note that’s a major second above the chord root as the tonic of your scale. For example, if the chord is a Bbmin7, use a C tritone scale.

If you want a good example of the tritone scale in action, the first part of Michael Brecker’s solo on “Quartet Number 3” in the Three Quartets album by Chic Corea is a tritone tour de force.

And with that, I’ll sign off. Practice hard, experiment, and have fun!

March 18, 2011 by
Filed Under: Jazz, Jazz Improvisation and Technique, Music, Saxophone Tagged With: , , , , , ,

Diminished Lick for Cycle of Dominants

The following pattern is nothing new. If you’ve worked at all on the diminished scale, you’ve doubtless encountered it. But have you worked it out in descending half-steps until it lies smoothly under your fingers from the top to the bottom of your horn? Because that root movement downward by minor seconds is what makes it, or any diminished pattern, particularly useful.

Let’s take a look at  why this is. First, here’s the lick:

Diminished Lick

Note that while each measure brings the diminished scale pattern progressively downward by a half-step, the corresponding chord progression is moving around the circle of fifths. Why?

Remember tritone substitution?

The diminished scale functions perfectly as a scale of choice for V7b9 chords and their tritone substitutes because of its symmetrical nature. Due to its structure, every diminished scale will accommodate not just one, but four possible V7b9 chords.

For instance, a half-step/whole-step diminished scale beginning on the note A will obviously work with an A7b9 chord. But it will also work equally well with C7b9, Eb7b9, and F#7b9.

Note that the A7b9 and Eb7b9 have roots a tritone apart, as do the C7b9 and F#7b9. In other words, tritone substitution is hardwired into the diminished scale.

Herein lies the magic of diminished scales descending by half-steps.

Look closely at the above diminished pattern and you’ll note that root movement downward by a half-step gives you the same scales that you’d arrive at with the circle of fifths.

For instance, in the first bar, the diminished pattern starting on the note C repeats itself sequentially a half-step down in the following measure, starting on the note B.

But what scale would you have arrived at if, instead of dropping a by a minor second, you had dropped by a perfect fifth to the note F, as you would do if you were moving around the circle of fifths? Guess what? You’d have the same scale–i.e. B, C, D, Eb, F, Gb, Ab, A. You’d just be starting on a different note of that scale.

Now, if you’re thinking…

…you’ll realize that because every diminished scale contains four possible roots, you can also achieve the results I’ve just described by moving upward by major seconds, another easy root movement.

You can also move down by a major third or a perfect fifth, but it’s easier to focus on the two root movements that are close at hand.

In summary

When woodshedding a diminished scale lick, it particularly behooves you to get it laying smoothly under your fingers in root movements of descending half-steps and ascending whole steps.

And that, Grasshopper, is that. The rest is up to you.

September 26, 2009 by
Filed Under: Jazz, Jazz Improvisation and Technique, Music, Saxophone Tagged With: , , , , , , , , , ,