The idea
A simple triad played over the core of a chord (usually the third and seventh of a dominant) produces a complex extended chord with a very easy fingering. The left hand plays the “shell,” the right hand a triad.
Over G7 (shell B–F, or G–B–F)
- A/G7 = G13(#11): A = 9, C# = #11, E = 13. Lydian-dominant sound, bright.
- E/G7 = G13(b9): E = 13, G# = b9, B = 3. “Broadway” sound, elegant tension.
- Eb/G7 = G7(#9, b13): Eb = b13, G = root, Bb = #9. Dark, modern blues.
- Db/G7 = G7(b9, #11): Db = #11, F = 7, Ab = b9. Very tense, octatonic.
- Bb/G7 = G7(#9): Bb = #9, D = 5, F = 7.
They all resolve to Cmaj7 or Cmaj9 (or to Am in A minor if the dominant is E7).
Over non-dominant chords
- D/C = Cmaj7(#11) without the seventh: Lydian.
- G/C = Cmaj9 (G B D over C).
- Em/C = Cmaj7.
- F/Dm = Dm7; Am/Dm = Dm9.
Tips
- The upper triad should sit above roughly C4: lower down the tensions get muddy.
- Lead the upper triad like a melody: between one chord and the next move the notes by step (A/G7 → G/C: A–G, C#–B, E–D).
- Use them in choirs: three high voices singing a triad over a different bass.
Real example
The language of upper structures is the bread and butter of modern jazz piano (Herbie Hancock, Bill Evans) and gospel organ; in R&B and K-pop ballads it is often heard in final cadences, when the piano plays E/G7 → G/C.