The One ThingPractising the Theory for Progressive and Jazz Guitarists

The key of C♯ minor

C♯ D♯ E F♯ G♯ A B

4 sharps: F♯ C♯ G♯ D♯. Relative major: The key of E major.

The triads of the key

i
C♯m

ii°
D♯°

III
E

iv
F♯m

v
G♯m

VI
A

VII
B

i7
C♯m7

iiø7
D♯m7♭5

IIImaj7
Emaj7

iv7
F♯m7

v7
G♯m7

VImaj7
Amaj7

VII7
B7

In practice the V of a minor key is almost always major, taken from the harmonic minor: G♯7 (V7), which carries the leading tone B♯.