In this etude I use three related triad shapes to “play over the bar line” from V to I. Take a look at the example below:
The triad shape, or color, is essentially the same in the first three measures. Specifically, E (major/minor) in the first measure, Ab (major/minor) in the second measure, and C (major/minor) in the third measure. I’m labeling these shapes “major/minor’ because both thirds of the triad are part of the shape. For example, the first measure has E, G, G# (stated enharmonically as Ab to make reading a little easier) and B.
As you can see, the relationship between these triad shapes is major thirds (or minor sixths, depending on how you look at it). In essence, the tonal relationship is a result of dividing the octave into three equal parts, giving it its symmetrical quality. This is the tonal foundation of the Coltrane Matrix, as well as the augmented scale.
If you look at the notes of the triad shapes over the V chord, you’ll see and hear some nice harmonic tensions (-9 and -13 and 3, specifically). But what really makes this line work is the forward energy of the shape itself, which “goes over the bar line” into the I chord very nicely. The fourth measure is simply a statement of the tonic major 7 chord (C major 7 in the example).
As with many symetrically related tonalities, you’ll find that these triad shapes appear in places over different chords as you play the exercise in all 12 keys. This is one of the advantages of working with symmetrically related tonalities: They help you recognize harmonic relationships and substitutions between dominant chords.
If you like the sound of this etude, and would like to explore more with symmetrically realted tonalities, please consider my e-books, The Coltrane Matrix, and Augmented Scale Diatonic Triad Pairs. Click on the link below to download the pdf of this etude and a midi version of the pdf for you to listen to.