F Mixolydian

F1G2A3B♭4C5D6E♭♭7

Major with a flattened seventh: the scale that fits a dominant seventh chord without altering it.

Written out

Fig. 2 · F Mixolydian, ascending

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

FWGWAHB♭WCWDHE♭WF

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

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

On the same tonic, F major 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.