guitar scale
A♭ blues
Minor pentatonic with one note squeezed in between the fourth and the fifth. It is written as a flattened fifth, so the fifth letter carries both of them and the fourth keeps its own.
The same sounds spelled from the other side are G♯ blues.
Written out
Every accidental is written in, rather than left to a key signature, so the letters can be read one at a time.
The step pattern
What is true of it
A♭ blues is A♭, C♭, D♭, E♭♭, E♭ and G♭, and back to A♭.
Its steps are W+H – W – H – H – W+H – W, where W is a whole step and H a half.
Written correctly it needs 7 alterations, E♭♭ among them. That is what the letters force, and it is also why nobody writes music in this key: the same notes spelled from the other side are easier to read.
Across the first twelve frets of the guitar its notes fall in 38 places, which is what makes a scale a shape rather than a list.
Chords made only of these notes
Found by testing every chord in the catalogue against these 6 sounds, not chosen.
Other scales on A♭
C bluesC♯ bluesD♭ bluesD bluesD♯ bluesE♭ bluesE bluesF bluesall 374