A major blues

A1B2C♭3C♯3E5F♯6

Major pentatonic with a flattened third added next to the third — the two live side by side rather than replacing each other.

Written out

Fig. 2 · A major blues, ascending

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

AWBHCHC♯W+HEWF♯W+HA

A major blues is A, B, C, C♯, E and F♯, and back to A.

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

Across the first twelve frets of the ukulele its notes fall in 27 places, which is what makes a scale a shape rather than a list.

Found by testing every chord in the catalogue against these 6 sounds, not chosen.