key signature
C♯ minor
C♯1D♯2E3F♯4G♯5A6B7
4 sharps, written F♯ C♯ G♯ D♯
The chords that live in it
C♯mdegree 1 · minorD♯dimdegree 2 · diminishedEdegree 3 · majorF♯mdegree 4 · minorG♯mdegree 5 · minorAdegree 6 · majorBdegree 7 · major
Built by stacking thirds inside the scale and asking what quality comes out, rather than from a table of roman numerals.
What is true of it
C♯ minor has 4 sharps.
They are written in this order, always: F♯ C♯ G♯ D♯.
Its notes are C♯, D♯, E, F♯, G♯, A and B.
Relative: E major has the same 4 sharps. Parallel: C♯ major has 7 sharps, which is why changing mode changes the signature by three.
Every key
C♭ majorG♭ majorD♭ majorA♭ majorE♭ majorB♭ majorF majorC majorG majorD majorA majorE majorB majorF♯ majorC♯ majorA♭ minorE♭ minorB♭ minorF minorC minorG minorD minorA minorE minorB minorF♯ minorG♯ minorD♯ minorA♯ minor