Manouche moves
The diminished on the dominant
Play a diminished 7 a half step above the dominant to get the ♭9 sound — the signature manouche colour.
The signature manouche colour over a dominant: a diminished 7 chord rooted a half step above it. Over E7, reach for F°.
F° = F, A♭, B, D. Lay those over an E7 and you get E7♭9 — the dark, urgent sound that runs through the whole tradition.
A diminished 7 is symmetric: F° = A♭° = B° = D° are all the same four notes. One shape covers four roots, so you can grab it almost anywhere on the neck.
Rule of thumb: see a dominant, reach for the diminished one fret above its root. Instant gypsy tension — and it resolves exactly where the plain dominant would.