D Phrygian dominant

D1E♭♭2F♯3G4A5B♭♭6C♭7

The fifth mode of harmonic minor: a flat second over a major third, so the step from the second to the third is a step and a half.

Written out

Fig. 2 · D Phrygian dominant, ascending

Every accidental is written in, rather than left to a key signature, so the letters can be read one at a time.

DHE♭W+HF♯HGWAHB♭WCWD

D Phrygian dominant is D, E♭, F♯, G, A, B♭ and C, and back to D.

Its steps are H – W+H – H – W – H – W – W, where W is a whole step and H a half.

On the same tonic, D Phrygian differs from it by exactly one note.

Across the first twelve frets of the ukulele its notes fall in 31 places, which is what makes a scale a shape rather than a list.

Found by testing every chord in the catalogue against these 7 sounds, not chosen.