Tools / Chords / C 9th

C 9th chord on guitar (C9)

Also written C9 or C

C 9th is built from C, E, G, B♭ and D. This advanced barre shape at the 7th fret requires a strong index barre and a muted high e string.

7th fret8-7-8-7-8-×

Positions on the neck1 of 5

How it’s built

C1Root

E3Major 3rd

G5Perfect 5th

B♭♭7Minor 7th

D99th

Formula 1, 3, 5, ♭7, 9

Positions on the neck1 of 5

Inversions

The same three notes, with a different one in the bass.

Root positionC–E–G–B♭–DC9Bass C

First inversionE–G–B♭–D–CC9/EBass E

Second inversionG–B♭–D–C–EC9/GBass G

Third inversionB♭–D–C–E–GC9/B♭Bass B♭

Fourth inversionD–C–E–G–B♭C9/DBass D

Why it sounds like that

C 9th combines a C major triad (1, 3, 5) with a minor seventh and a major ninth: 1, 3, 5, ♭7, 9. The ♭7 B♭ and 9 D give it a dominant quality. Compare it with C 7th, which lacks the ninth.

What goes wrong with C 9th?

Letting the index barre collapse so the G string buzzes at fret 7.
Allowing the high e string to ring open, which adds an unwanted E above the chord.
Placing the ring finger on the G string instead of the D string, losing the fifth.

When to use it

C 9th functions as the dominant in F major, appearing in progressions like F–B♭–C–F (I–IV–V–I). It suits blues, funk and jazz-rock. Compare it with C major to hear how the seventh and ninth add tension.

Changing to and from C 9th

Move to B♭ 9th by sliding the shape down two frets to the 5th fret.
Move to C♯ 9th by sliding the shape up one fret to the 8th fret.

Which voicing to use

The 7th fret and 8th fret voicings both have C in the bass, but the 8th fret version adds the ninth on top. The C9/E inversion places the third in the bass for a smoother sound.

How do you play a C 9th chord on guitar?

7th fret

Barre● On the diagram

C 9th is played at the 7th fret as 8 7 8 7 8 ×: barre your index finger across fret 7, middle finger on the low E string at fret 8, ring finger on the D string at fret 8 and pinky finger on the B string at fret 8. The high e string stays muted.

Tip — The index barre must fret the A string and the G string cleanly while the pinky reaches fret 8 on the B string.

String-by-string breakdown

String	Fret	Finger	Note
6 (E)	8	2	C (1)
5 (A)	7	1 (barre)	E (3)
4 (D)	8	3	B♭ (♭7)
3 (G)	7	1 (barre)	D (9)
2 (B)	8	4	G (5)
1 (e)	muted	—	—

8th fret

Barre

C 9th is played at the 8th fret as 8 10 8 9 8 10: barre your index finger across fret 8, ring finger on the A string at fret 10, middle finger on the G string at fret 9 and pinky finger on the high e string at fret 10.

String-by-string breakdown

String	Fret	Finger	Note
6 (E)	8	1 (barre)	C (1)
5 (A)	10	3	G (5)
4 (D)	8	1 (barre)	B♭ (♭7)
3 (G)	9	2	E (3)
2 (B)	8	1 (barre)	G (5)
1 (e)	10	4	D (9)

C9/E inversion · 0-1-0-0-1-0

Beginner

C 9th is played in open position as 0 1 0 0 1 0: index finger on the A string at fret 1 and middle finger on the B string at fret 1. The low E, D, G and high e strings ring open.

String-by-string breakdown

String	Fret	Finger	Note
6 (E)	open	—	E (3)
5 (A)	1	1	B♭ (♭7)
4 (D)	open	—	D (9)
3 (G)	open	—	G (5)
2 (B)	1	2	C (1)
1 (e)	open	—	E (3)

C9/E inversion · 0-1-0-0-1-3

Beginner

C 9th is played in open position as 0 1 0 0 1 3: index finger on the A string at fret 1, middle finger on the B string at fret 1 and ring finger on the high e string at fret 3. The low E, D and G strings ring open.

String-by-string breakdown

String	Fret	Finger	Note
6 (E)	open	—	E (3)
5 (A)	1	1	B♭ (♭7)
4 (D)	open	—	D (9)
3 (G)	open	—	G (5)
2 (B)	1	2	C (1)
1 (e)	3	3	G (5)

C9/E inversion · 0-1-0-3-1-3

Beginner

C 9th is played in open position as 0 1 0 3 1 3: index finger on the A string at fret 1, ring finger on the G string at fret 3, middle finger on the B string at fret 1 and pinky finger on the high e string at fret 3. The low E and D strings ring open.

String-by-string breakdown

String	Fret	Finger	Note
6 (E)	open	—	E (3)
5 (A)	1	1	B♭ (♭7)
4 (D)	open	—	D (9)
3 (G)	3	3	B♭ (♭7)
2 (B)	1	2	C (1)
1 (e)	3	4	G (5)

Common questions

How is C 9th written?

C 9th is written as C9. The symbol C9 always means a dominant ninth chord with a minor seventh and a major ninth.

What is the difference between C 9th and C add 9?

C 9th includes the minor seventh B♭, while C add 9 is a C major triad with the ninth D added and no seventh. The add 9 sounds more consonant and less bluesy.

Why does the C9/E inversion have a different bass note?

The C9/E inversion places the third, E, in the bass instead of the root C. This creates a smoother stepwise bass line when moving between chords in F major.

String

Fret

Finger

Note

6 (E)

C (1)

5 (A)

1 (barre)

E (3)

4 (D)

B♭ (♭7)

3 (G)

1 (barre)

D (9)

2 (B)

G (5)

1 (e)

muted

—

String

Fret

Finger

Note

6 (E)

1 (barre)

C (1)

5 (A)

G (5)

4 (D)

1 (barre)

B♭ (♭7)

3 (G)

E (3)

2 (B)

1 (barre)

G (5)

1 (e)

D (9)

String

Fret

Finger

Note

6 (E)

open

—

E (3)

5 (A)

B♭ (♭7)

4 (D)

open

—

D (9)

3 (G)

open

—

G (5)

2 (B)

C (1)

1 (e)

open

—

E (3)

String

Fret

Finger

Note

6 (E)

open

—

E (3)

5 (A)

B♭ (♭7)

4 (D)

open

—

D (9)

3 (G)

open

—

G (5)

2 (B)

C (1)

1 (e)

G (5)

String

Fret

Finger

Note

6 (E)

open

—

E (3)

5 (A)

B♭ (♭7)

4 (D)

open

—

D (9)

3 (G)

B♭ (♭7)

2 (B)

C (1)

1 (e)

G (5)