C9 Guitar Chord

C9 is the C dominant ninth chord. It has five notes on paper: C, E, G, B flat and D. On guitar the standard shape leaves out the G, because four strings and four fingers cannot hold all five and the fifth is the note a ninth chord can spare.

Root on the A string at the 3rd fret with no barre. Four strings: root, third, flat seventh and ninth. The fifth is left out.

How to play C9, step by step

Index finger: 2nd fret, D string
Middle finger: 3rd fret, A string
Ring finger: 3rd fret, G string
Pinky finger: 3rd fret, B string
Strum only the A and D and G and B strings, and stop the downstroke at the B.

Keep this shape on four strings and mute it with the palm between strums. A ninth chord played as a percussive chop is one of the core sounds of funk rhythm guitar.

More ways to play C9

There are 2 common C9 shapes in total: the standard one at the top of the page, plus these, easiest first. You only ever need one. Tap any card to hear it.

C9 guitar chord diagram, barre at fret 8, played 8 x 8 9 8 10 — Barre at fret 8

If it sounds cluttered

The low E rings: It is not in the shape and it sits below the root. Mute it with the index fingertip or start the strum on the A string.
The high E rings: Only four strings belong here. Let the pinky lean far enough to deaden the high E, and stop the strum at the B.
The chord sounds like a mess: Three fingers sit at the 3rd fret and one at the 2nd. Check each string one at a time: you should hear C, E, B flat, D.

What makes it a C9

C · E · G · B♭ · D 1 3 5 ♭7 9

C9 is a C7 chord with a ninth added. C7 is C, E, G and B flat; adding the D above it makes C9. The B flat is what makes the chord restless and the D is what makes it sound rich rather than raw.

Its usual job is the V chord of F, and it is the standard I chord of a blues in C. Because the ninth softens the dominant seventh without weakening its pull, blues, soul and funk players use ninths where a plainer style would use sevenths.

C9 vs C7

C9 is C7 with one extra note, the D. Both want to move to F, but C7 sounds rough and vocal while C9 sounds smooth and arranged.

The shapes are close on the neck. C7 as x32310 and C9 as x3233x share a hand position, so it is worth playing them back to back to hear what the ninth adds.

C9 chord questions

What is the difference between C9 and Cadd9?

C9 contains a B flat, the flat seventh, and sounds like a blues or funk chord that wants to resolve. Cadd9 has no seventh at all: it is a plain C major with a D added, and it sounds bright and settled. They are completely different chords despite the similar names.

Why is the fifth missing from this shape?

A ninth chord has five notes and the hand has four fingers. The fifth carries the least information, so it is the note dropped first. The chord still sounds unmistakably like C9.

Is C9 the same as C7?

No. C9 adds a D on top of C7. The two are close relatives and often interchangeable in a blues, but the ninth is a distinctly smoother sound.

Where is C9 used?

As the V chord in F, as the I chord in a blues in C, and all through funk and soul, where ninth chords are the normal way to voice a dominant chord.

Which strings do I strum?

The A, D, G and B strings. Keep the low E and high E quiet with the fretting hand.