guitar scale
A Dorian
A1B2C♭3D4E5F♯6G♭7
Minor with a natural sixth. The second mode of the major scale.
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
AWBHCWDWEWF♯HGWA
What is true of it
A Dorian is A, B, C, D, E, F♯ and G, and back to A.
Its steps are W – H – W – W – W – H – W, where W is a whole step and H a half.
On the same tonic, A natural minor differs from it by exactly one note.
Across the first twelve frets of the guitar its notes fall in 48 places, which is what makes a scale a shape rather than a list.
Chords made only of these notes
CmajorCmaj7major seventhDmajorD7dominant seventhEmminorEm7minor seventhF♯dimdiminishedF♯m7♭5half-diminished seventh
Found by testing every chord in the catalogue against these 7 sounds, not chosen.