Barry Harris Diminished 6th Theory

#people/Barry_Harris was a brilliant musician and theorist, and I’ve been studying his ideas about how to incorporate his particular musical elements into my own music for a while now. I keep forgetting all of the things that I’m learning so I’m leveraging my notes to really help these things stick.

This is sort of an evolution on my Comping with chord scales idea. This note is lengthy, so the Barry Harris diminished 6th theory#Crossings section down below can help with some further reading/refreshers.

The Three Scales

Harris identifies three scales, each of which consists of a tonic chord and an accompanying diminished chord.

The three scales are based around the three most common chord types we see in music: major, minor, and dominant. Each scale is devised in such a way as to emphasize certain things:

They Divide Evenly Horizontally

The typical scale pattern consists of 7 different tones, meaning that in a bar of 4/4 we have to repeat our starting note to make it “fit”, Harris’ scale has 8 tones, meaning we end our scale on the downbeat of the following measure.

The Divide Evenly Vertically

We create chords by stacking notes, and in jazz the most common chord is a tetrad, rather than a triad. Thus, a scale that divides into two tetrads, rather than in even triads, is called for.

We Prioritize the add6 Chord as a Tonic Sonority

Rather than the 7th as our “default“extension of tetrad, we use the 6th for our major and minor chords. For dominants, the 7th is still present to preserve its function, but we can use 6ths (spelled as 13ths).

Because We Are Dividing Things Evenly, We Alternate Between “in” and “out” Notes

Our 1 note is in the tonic chord, 2 in the diminished, 3 in the tonic, and so on.

Our Tonic Tetrad and Neighbor Tetrad is a Set of Interlocking 5ths

This promotes certain amount of stability, with 5ths being considered the most stable sounding discrete interval (in other words, most stable aside from unisons and octaves). The 5ths aren’t always perfect, but the relationship between the tritone is inportant and does a similarly strong job of imparting character. Using the note C as an example:

• C6: C E G A ({C G} {E A})
• Cm6: C Eb G A ({C G} {Eb A})
• C7: C E G Bb ({C G} {E Bb})

And our neighbor:

• D°: D F Ab C ({D Ab} {F C})

Harmony is a Consequence of Melody

This harkens back to the composers of the renaissance and baroque eras, wherein priority was placed on the way lines moved across time rather than in blocks.

All of Functional Harmony is Preserved

However, we gain access to certain tensions and simpler ways of thinking about them that allow them to spring to mind more naturally.

Building the Scales

The scales are the important thing here and learning what they are is key. The major scale is the “default” that we are deviating from. They are built as follows:

Major: 1 2 3 4 5 b6 6 7

Minor: 1 2 b3 4 5 b6 6 7

Dominant: 1 2 3 4 5 6 b7 7

These scales are also commonly called “bebop scales,” but they’re doing a little more than what people typically use them for.

Patterns I Like to Practice

Because we are alternating between our tonic and diminished neighbor, we can simply play the scale in various polyphonic ways and make some really interesting sounds.

Contrary Motion with Two Voices

One I like is two voices moving in contrary motion until they reach the octave. There are some great sounds they come out of this and the pattern contains some surprisingly consistent and simple patterns.

For example, if we were to start with the C major scale our notes would be:

C D E F G Ab A B

And organized in this pattern we would have:

To help us understand it, we can looks little deeper and discover a few different things.

One, and perhaps most obvious, is that we have a andmark right in the middle: we play an octave on the fifth note of the scale. This is true for every permutation of this! We will play an octave exactly in the middle of every scale we play in this way.

Two, perhaps less obvious, is that we are also either playing half of our “in” chord (tonic) or our “out” chord (diminished neighbor).

Third, if we look at the intervals themselves, we also find that we are alternating between “perfect” and “imperfect” intervals. That is, intervals of the unison, 4th, 5th, and 8ve, and intervals of the 3rd and 6th. If we were to simplify it and remove inversions, we are alternating between 3rds and 4ths.

Putting it all together we have this:

Starting on the root:

As stated, as long as we start with our “in” chord doesn’t matter where we start, this pattern will hold (basically) true.

Starting on the 3rd:

Starting on the 5th:

Starting on the 6th:

There’s one more pattern here that I find really cool: the scale patterns themselves are inversions of one another!

Because our tonic tetrad is a set of interlocking 5ths (C E G A = {C G} {E A}) our landmark octave will always be the corresponding 5th/4th away from our root.

The only things that change when we start on a member of our diminished neighbor is the order of intervals and in/out, and the presence of more dissonances for our imperfect and perfect intervals.

For example, starting from the root of our D diminished:

Notice how rather than a series of consonant intervals, we are loaded up with way more dissonant ones; our 5th and 4th are diminished and augmented, respectively, and we have introduced a 2nd/7th interval.

Because our neighbor is symmetrical, this will be true for all of our inversions

Our first pattern emphasizes the tonic chord whereas the second pattern emphasizes the neighbor chord.

Crossings

X:: Thomas Echols' Elevator