Tools / Chords / C♯ add 9

C♯ add 9 chord on bass (C♯add9)

Also written C♯add9, C♯ or C♯ Add 9th

C♯ add 9 is built from C♯, E♯, G♯, and D♯. This advanced voicing sits high on the neck, demanding precise finger placement.

C♯add9/D♯ inversion11-11-11-10

How it’s built

C♯1Root

E♯3Major 3rd

G♯5Perfect 5th

D♯99th

Formula 1, 3, 5, 9

Inversions

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

Root positionC♯–E♯–G♯–D♯C♯add9Bass C♯

First inversionE♯–G♯–D♯–C♯C♯add9/E♯Bass E♯

Second inversionG♯–D♯–C♯–E♯C♯add9/G♯Bass G♯

Third inversionD♯–C♯–E♯–G♯C♯add9/D♯Bass D♯

Why it sounds like that

C♯ add 9 uses the formula 1, 3, 5, 9. The major 2nd between C♯ and D♯ adds the ninth, while the major 3rd from C♯ to E♯ gives the major quality. Compare it with C♯ major, which omits the ninth.

What goes wrong with C♯ add 9?

Letting the index finger mute the G string by collapsing.
Pressing too hard with the pinky, causing the D string to buzz.

When to use it

C♯ add 9 is the tonic in C♯ major, fitting the I–IV–V–I progression: C♯ major–F♯ major–G♯ major–C♯ major. It suits rock, pop, and gospel styles where the ninth adds brightness. It also works over C♯ major and C♯ 5th chords.

Changing to and from C♯ add 9

Slide the shape down one fret to the 9th fret for C add 9.
Move to C♯ major by lifting the index finger and playing the open C♯ string.

Which voicing to use

The default voicing places D♯ in the bass, softening the root emphasis. Use this inversion when the bass line needs to connect stepwise or when the root is covered by another instrument.

How do you play a C♯ add 9 chord on bass?

C♯add9/D♯ inversion

Intermediate● On the diagram

C♯ add 9 is played at the 10th fret as 11 11 11 10: middle finger on the E string at fret 11, ring finger on the A string at fret 11, pinky finger on the D string at fret 11 and index finger on the G string at fret 10.

Tip — The stretch between the index finger on the 10th fret and the pinky on the 11th fret of the D string is wide.

String-by-string breakdown

String	Fret	Finger	Note
4 (E)	11	2	D♯ (9)
3 (A)	11	3	G♯ (5)
2 (D)	11	4	C♯ (1)
1 (G)	10	1	E♯ (3)

Common questions

How is C♯ add 9 written?

C♯ add 9 is written as C♯add9 or C♯. The ASCII root is C#. It is also spelled D♭ in enharmonic notation for the same sounding root.

How does C♯ add 9 differ from C♯ major?

C♯ add 9 includes the ninth, D♯, which C♯ major omits. The added note creates a brighter, more open sound while keeping the major third.

Can C♯ add 9 be used in minor keys?

C♯ add 9 is diatonic to E♭ natural minor and B♭ natural minor. In those keys it acts as a borrowed major chord, often for modal interchange.

String

Fret

Finger

Note

4 (E)

D♯ (9)

3 (A)

G♯ (5)

2 (D)

C♯ (1)

1 (G)

E♯ (3)