C♯ 9th chord on guitar (C♯9)

Also called or written C♯9 or C♯

C♯ 9th is built from C♯, E♯, G♯, B and D♯. This advanced barre shape at the 8th fret needs a solid index barre and a muted high e string.

8frC♯E♯BD♯G♯EADGBE
Positions on the neck1 of 5
Practice C♯ 9th chord

How it is built

C♯RootE♯Major thirdG♯Perfect fifthBMinor seventhD♯Ninth

Formula 1, 3, 5, ♭7, 9

Inversions
  • Root positionC♯–E♯–G♯–B–D♯C♯99-8-9-8-9-×
  • First inversionE♯–G♯–B–D♯–C♯C♯9/E♯1-2-1-1-2-1
  • Second inversionG♯–B–D♯–C♯–E♯C♯9/G♯no shape on this instrument
  • Third inversionB–D♯–C♯–E♯–G♯C♯9/B×-2-1-1-2-1
  • Fourth inversionD♯–C♯–E♯–G♯–BC♯9/D♯×-6-6-6-6-7

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

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

Full note and interval breakdown
StringFretFingerNote
6 (E)92C♯ (1)
5 (A)81 (barre)E♯ (3)
4 (D)93B (♭7)
3 (G)81 (barre)D♯ (2)
2 (B)94G♯ (5)
1 (e)muted

AdvancedThe index barre must fret the A string and the G string cleanly while the pinky reaches fret 9 on the B string.

9th fret

C♯ 9th is played at the 9th fret as 9 11 9 10 9 11: barre your index finger across fret 9, ring finger on the A string at fret 11, middle finger on the G string at fret 10 and pinky finger on the high e string at fret 11.

Full note and interval breakdown
StringFretFingerNote
6 (E)91 (barre)C♯ (1)
5 (A)113G♯ (5)
4 (D)91 (barre)B (♭7)
3 (G)102E♯ (3)
2 (B)91 (barre)G♯ (5)
1 (e)114D♯ (2)

C♯9/E♯ inversion · fret 1

C♯ 9th is played at the 1st fret as 1 2 1 1 2 1: barre your index finger across fret 1, ring finger on the A string at fret 2 and pinky finger on the B string at fret 2.

Full note and interval breakdown
StringFretFingerNote
6 (E)11 (barre)E♯ (3)
5 (A)23B (♭7)
4 (D)11 (barre)D♯ (2)
3 (G)11 (barre)G♯ (5)
2 (B)24C♯ (1)
1 (e)11 (barre)E♯ (3)

C♯9/E♯ inversion · fret 8

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

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)81 (barre)E♯ (3)
4 (D)92B (♭7)
3 (G)81 (barre)D♯ (2)
2 (B)93G♯ (5)
1 (e)94C♯ (1)

C♯9/E♯ inversion · fret 11

C♯ 9th is played at the 11th fret as 13 11 11 13 12 11: barre your index finger across fret 11, ring finger on the low E string at fret 13, pinky finger on the G string at fret 13 and middle finger on the B string at fret 12.

Full note and interval breakdown
StringFretFingerNote
6 (E)133E♯ (3)
5 (A)111 (barre)G♯ (5)
4 (D)111 (barre)C♯ (1)
3 (G)134G♯ (5)
2 (B)122B (♭7)
1 (e)111 (barre)D♯ (2)

Why it sounds like that

C♯ 9th stacks 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♯ create a dominant sound. Compare it with C♯ 7th, which omits the ninth.

What goes wrong with C♯ 9th?

  • Letting the index barre sag so the G string buzzes at fret 8.
  • Allowing the high e string to ring open, adding an E that is not in the chord.
  • Placing the ring finger on the G string instead of the D string, losing the fifth.

When to use it

C♯ 9th acts as the dominant in F♯ major, used in progressions like F♯–B–C♯–F♯ (I–IV–V–I). It suits blues, rock and jazz-funk. 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 6th fret.
  • Move to D 9th by sliding the shape up one fret to the 9th fret.

Which voicing to use

The 8th fret and 9th fret voicings both have C♯ in the bass, but the 9th fret version adds the ninth on top. The C♯9/E♯ inversion places the third in the bass for smoother voice-leading.

Other C♯ chords

Common questions

How is C♯ 9th written?

C♯ 9th is written as C♯9 or C#9. The symbol C♯9 always means a dominant ninth chord with a minor seventh and a major ninth. It is also spelled D♭ in enharmonic notation for the same sounding root.

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 open and less tense.

Why does the C♯9/E♯ inversion have a different bass note?

The C♯9/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.