C-sharp minor is a minor scale based on C♯, with the pitches C♯, D♯, E, F♯, G♯, A, and B. Its key signature consists of four sharps.
The C-sharp natural minor scale is:

Changes needed for the melodic and harmonic versions of the scale are written in with accidentals as necessary. The C-sharp harmonic minor and melodic minor scales are:

Its relative major is E major. Its parallel major, C-sharp major, is usually written instead as the enharmonic key of D-flat major, since C-sharp major’s key signature with seven sharps is not normally used. Its enharmonic equivalent, D-flat minor, having eight flats including the B, has a similar problem. Therefore, C-sharp minor is often used as the parallel minor for D-flat major. (The same enharmonic situation occurs with the keys of A-flat major and G-sharp minor, and in some cases, with the keys of G-flat major and F-sharp minor.)

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