guitar scale
G♭ Dorian
Minor with a natural sixth. The second mode of the major scale.
The same sounds spelled from the other side are F♯ Dorian.
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
G♭ Dorian is G♭, A♭, B♭♭, C♭, D♭, E♭ and F♭, and back to G♭.
Its steps are W – H – W – W – W – H – W, where W is a whole step and H a half.
Written correctly it needs 8 alterations, B♭♭ 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.
On the same tonic, G♭ natural minor differs from it by exactly one note.
Across the first twelve frets of the guitar its notes fall in 46 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 7 sounds, not chosen.