D Locrian

D1E♭♭2F♭3G4A♭♭5B♭♭6C♭7

The only mode of the major scale whose fifth is diminished, which is why its tonic chord cannot rest.

Written out

Fig. 2 · D Locrian, ascending

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

DHE♭WFWGHA♭WB♭WCWD

D Locrian is D, E♭, F, G, A♭, B♭ and C, and back to D.

Its steps are H – W – W – H – W – 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 30 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.