piano scale
C♯ Dorian
C♯1D♯2E♭3F♯4G♯5A♯6B♭7
Minor with a natural sixth. The second mode of the major scale.
The same sounds spelled from the other side are D♭ 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
C♯WD♯HEWF♯WG♯WA♯HBWC♯
What is true of it
C♯ Dorian is C♯, D♯, E, F♯, G♯, A♯ and B, and back to C♯.
Its steps are W – H – W – W – W – H – W, where W is a whole step and H a half.
On the same tonic, C♯ natural minor differs from it by exactly one note.
Chords made only of these notes
C♯mminorC♯m7minor seventhD♯mminorD♯m7minor seventhEmajorEmaj7major seventhF♯majorF♯7dominant seventh
Found by testing every chord in the catalogue against these 7 sounds, not chosen.