Upper structures and scales use the same notes; the difference is the direction you think in. A scale runs the notes stepwise: 1, 2, 3, 4, 5, 6, 7. An upper structure stacks them in thirds above the chord: 1, 3, 5, 7 underneath, then 9, 11 and 13 on top, and that top half is a chord of its own. Cm7 with a 9th gives you an E♭maj7 arpeggio on top. Cmaj7 heard from its 6th gives you Am7 and its extensions. Junewon Choi showed this on a VoiceLid Jazz Guitar live stream, and it is why our online jazz guitar lessons teach the fretboard through stacked chords instead of scale patterns.
Is an Upper Structure Just a Scale in Disguise?
Write out C major in thirds from C: C, E, G, B, D, F, A. The bottom four notes are Cmaj7, the chord tones. The top three are the 9th, 11th and 13th, the tensions or avoid notes. Now write the same seven notes stepwise and you have the C major scale.
Nothing is added or taken away. The concept is different. Stepwise, the notes are a scale you run up and down. Stacked, they are a chord with another chord above it. Junewon's point is that jazz itself developed in the stacked direction: triads, then sevenths with the blues, then tensions with Charlie Parker's bebop. So thinking and playing upward is more organic for jazz than treating the same notes as a scale. For the bebop side of this story, read Decoding Bebop: Upper Structure Triads and the Architecture of Modern Jazz.
How Did Wes Montgomery Hear a Major Chord?
Play the C major triad in a compact position and keep stacking: C, E, G, B, D. That line is already what Junewon calls the Wes Line. But Wes usually didn't think of it as major. He took the A at the top of the stack and moved it to the bottom, so the notes read A, C, E, G, B, D: Am7 with its 9th and 11th. Cmaj7 sits inside that stack.
So over Cmaj7 Wes was thinking A minor, a third below, with major and minor in the same picture. The notes are diatonic to C major either way; the point is that the shape is a chord stack, not a scale run, and it moves diagonally across the strings rather than staying in one box.
What Does Django's Line Have to Do With Upper Structures?
Django Reinhardt lost the use of two fingers on his fretting hand after a caravan fire, and still became one of the first guitarists to tour the world. The line associated with him, the Django Line, is a major 7 arpeggio played with two fingers, repeating in octaves at high speed.
Here is the harmony behind it. Start with Cm7: C, E♭, G, B♭. Add the 9th, D. Leave out the root and the top four notes are E♭, G, B♭, D: E♭maj7. So the Django Line over C minor is the upper structure of Cm7(9). Junewon shows it with the middle finger on the E♭ inside the C minor shell voicing, then adds the 5th and the 9th on top.
The same shape runs through the jazz guitar lineage:
Django Reinhardt: the two-finger major 7 arpeggio, very fast.
George Benson: often plays it the other way, ascending.
Wes Montgomery: plays it in octaves.
Pat Martino and Russell Malone: use it constantly, Martino especially from minor shapes.
For a side-by-side of the two lines, see Django Line vs. Wes Line: Understanding the Difference. If you want the complete voicing system behind upper structures, the Bridge Series shows how they connect to chord function.
Why Does This Push You Across the Neck?
Because a stack of thirds doesn't fit inside one box. Even the classical tradition knew this. Andrés Segovia's scale studies, which you can find online, shift position on the third or fourth string so one scale covers the whole neck instead of sitting in one position. Upper structures go further: every arpeggio climbs to the next string set and the next position, which is exactly why Junewon asks students to read the fretboard diagonally.
How Do You Practice It?
Choose one chord: Cm7. Play the shell voicing (C, E♭, B♭).
Add the 5th and 9th and find E♭maj7 on top.
Play E♭maj7 as a two-finger arpeggio, Django style, then repeat it an octave higher.
Reverse it and play it ascending like Benson, then as octaves like Wes.
Do the same over Cmaj7 by thinking Am7 a third below.
Use both sounds on a tune: in I'll Be Seeing You, the bar that sounds like C minor can be played as E♭maj7.
Once you hear chords this way, the scale is still there, but it stops being the thing you think about. You think about the chord on top. If you want to build this from the ground up as a system across the whole fretboard, Fundamental 1: Wes Diagonal System lays out the Functional Diagonal Approach step by step.
About the Author
Junewon Choi is a Berklee-trained jazz guitarist and the founder of VoiceLid Jazz Guitar, an online education platform teaching jazz harmony and improvisation through the Functional Diagonal Approach (FDA) — a chord-first method built on voice-leading rather than scale boxes.
Wes' Insight — Wes Montgomery's fretboard logic, in lesson form
Fundamental 1: Wes Diagonal System — the FDA from the ground up