piano scale
C♯ harmonic minor
C♯1D♯2E♭3F♯4G♯5A♭6B♯7
Natural minor with the seventh raised, which buys a leading note and pays for it with a step and a half between the sixth and seventh.
The same sounds spelled from the other side are D♭ harmonic minor.
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♯HAW+HB♯HC♯
What is true of it
C♯ harmonic minor is C♯, D♯, E, F♯, G♯, A and B♯, and back to C♯.
Its steps are W – H – W – W – H – W+H – H, 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♯mminorD♯dimdiminishedD♯m7♭5half-diminished seventhEaugaugmentedF♯mminorF♯dimdiminishedF♯m7minor seventhF♯m7♭5half-diminished seventh
Found by testing every chord in the catalogue against these 7 sounds, not chosen.
Other scales on C♯
C harm minD harm minD♯ harm minE♭ harm minE harm minF harm minF♯ harm minG♭ harm minall 374