C major pentatonic

C1D2E3G5A6

The major scale without its two half steps. Five notes, and no pair of them a half step apart.

Written out

Fig. 2 · C major pentatonic, ascending

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

CWDWEW+HGWAW+HC

C major pentatonic is C, D, E, G and A, and back to C.

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

It uses no sharps and no flats at all: seven letters, seven white keys.

Across the first twelve frets of the ukulele its notes fall in 24 places, which is what makes a scale a shape rather than a list.

Found by testing every chord in the catalogue against these 5 sounds, not chosen.