Key reference

The key of C minor

3 flats · C – D – E♭ – F – G – A♭ – B♭

C minor has 3 flats: B♭, E♭, A♭. A piece in this key draws on C, D, E♭, F, G, A♭, B♭ and treats C as home.

The seven chords below are the ones built from those notes alone, which is why they sound like they belong together.

The key signature

Treble clef.

Bass clef.

The key signature of C minor is B♭, E♭, A♭, written in that order in both clefs.

Order of flats

B♭
E♭
A♭
D♭
G♭
C♭
F♭

This signature uses the first 3 of them: B♭, E♭, A♭.

The notes of the key

These are the notes of the natural minor scale on this tonic. Pieces in a minor key routinely raise the seventh, and sometimes the sixth, without changing the signature. See the C minor scale for the degrees and step pattern.

C – D – E♭ – F – G – A♭ – B♭

The seven diatonic chords

Build a triad on each degree using only notes from the key and the qualities fall into a fixed pattern. That pattern is the same in every minor key, which is why progressions transpose so cleanly.

Degree	Roman	Chord	Notes	Function
1	i	Cm	C – E♭ – G	Tonic
2	ii°	Ddim	D – F – A♭	Predominant
3	III	E♭	E♭ – G – B♭	Tonic
4	iv	Fm	F – A♭ – C	Predominant
5	v	Gm	G – B♭ – D	Dominant
6	VI	A♭	A♭ – C – E♭	Tonic
7	VII	B♭	B♭ – D – F	Subtonic

Adding sevenths

Stack one more third on each and you get the seventh chords of the key.

Roman	Chord	Notes
i7	Cm7	C – E♭ – G – B♭
iiø7	Dm7♭5	D – F – A♭ – C
IIImaj7	E♭maj7	E♭ – G – B♭ – D
iv7	Fm7	F – A♭ – C – E♭
v7	Gm7	G – B♭ – D – F
VImaj7	A♭maj7	A♭ – C – E♭ – G
VII7	B♭7	B♭ – D – F – A♭

Common progressions in C minor

These are the same shapes you meet in every minor key, written with this key’s chords.

One caveat: the chords below are the strictly diatonic ones. In practice the chord on the fifth degree is usually raised to major (borrowing the leading tone from harmonic minor), because the natural minor’s minor v has no leading tone and so does not pull back to the tonic.

i – VI – III – VII

CmiTonic
A♭VITonic
E♭IIITonic
B♭VIISubtonic

i – iv – v – i

CmiTonic
FmivPredominant
GmvDominant
CmiTonic

i – VII – VI – V

CmiTonic
B♭VIISubtonic
A♭VITonic
GmvDominant

To hear them, play a progression below. It starts in C minor; change the key and the chord symbols change while the numerals stay put.

Related keys

Relationship	Key	Signature
Relative major	E♭ major	Same signature
Parallel major	C major	no sharps or flats
One step clockwise (a fifth up)	G minor	One fewer flat
One step counter-clockwise (a fifth down)	F minor	One more flat

Neighbouring keys on the circle of fifths share six of their seven notes.

Try it · choose a key

E♭ major · relative minor C minor

Key signature: 3 flats: B♭, E♭, A♭.

E♭ major scale: E♭ F G A♭ B♭ C D
C minor (natural): C D E♭ F G A♭ B♭
Clockwise: the dominant key (V): B♭ major, a fifth above — one fewer flat.
Counter-clockwise: the subdominant key (IV): A♭ major, a fifth below — one more flat.

E♭ major scale Key of E♭ major Key of C minor

C minor on the circle of fifths, at the position it shares with its relative major. Choose any other key to compare its signature and neighbours.