piano scale
D♭ 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 C♯ 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
D♭ blues is D♭, F♭, G♭, A♭♭, A♭ and C♭, and back to D♭.
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, A♭♭ 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.
Chords made only of these notes
Found by testing every chord in the catalogue against these 6 sounds, not chosen.
Other scales on D♭
C bluesD bluesD♯ bluesE♭ bluesE bluesF bluesF♯ bluesG♭ bluesall 374