Key reference

The key of C major

no sharps or flats · C – D – E – F – G – A – B

C major has no sharps or flats. 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 major is empty: no sharps or flats.

Order of sharps

F♯
C♯
G♯
D♯
A♯
E♯
B♯

This key signature has no sharps or flats.

The notes of the key

These are the notes of the major scale on this tonic. See the C major 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 major key, which is why progressions transpose so cleanly.

Degree	Roman	Chord	Notes	Function
1	I	C	C – E – G	Tonic
2	ii	Dm	D – F – A	Predominant
3	iii	Em	E – G – B	Tonic
4	IV	F	F – A – C	Predominant
5	V	G	G – B – D	Dominant
6	vi	Am	A – C – E	Tonic
7	vii°	Bdim	B – D – F	Dominant

Adding sevenths

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

Roman	Chord	Notes
Imaj7	Cmaj7	C – E – G – B
ii7	Dm7	D – F – A – C
iii7	Em7	E – G – B – D
IVmaj7	Fmaj7	F – A – C – E
V7	G7	G – B – D – F
vi7	Am7	A – C – E – G
viiø7	Bm7♭5	B – D – F – A

Common progressions in C major

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

I – V – vi – IV

CITonic
GVDominant
AmviTonic
FIVPredominant

I – vi – IV – V

CITonic
AmviTonic
FIVPredominant
GVDominant

ii – V – I

DmiiPredominant
GVDominant
CITonic

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

Related keys

Relationship	Key	Signature
Relative minor	A minor	Same signature
Parallel minor	C minor	3 flats
One step clockwise (a fifth up)	G major	One more sharp
One step counter-clockwise (a fifth down)	F major	One more flat

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

Try it · choose a key

C major · relative minor A minor

Key signature: No sharps or flats.

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

C major scale Key of C major Key of A minor

C major on the circle of fifths. Choose any other key to compare its signature and neighbours.