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C♯ 7th suspended 4th chord on bass (C♯7sus4)
Also called or written C♯7sus4, C♯ or C♯ Dominant 7th Suspended 4th
C♯ 7th suspended 4th contains C♯, F♯, G♯, and B. The 9th-fret shape demands a wide stretch, and the 4th-fret inversion requires a full barre.
How it is built
Formula 1, 4, 5, ♭7
How do you play a C♯ 7th suspended 4th chord on bass?
C♯ 7th suspended 4th is played at the 9th fret as 9 11 9 11: index finger on the E string at fret 9, ring finger on the A string at fret 11, middle finger on the D string at fret 9 and pinky finger on the G string at fret 11.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 9 | 1 | C♯ (1) |
| 3 (A) | 11 | 3 | G♯ (5) |
| 2 (D) | 9 | 2 | B (♭7) |
| 1 (G) | 11 | 4 | F♯ (4) |
AdvancedThe 4th-fret inversion requires barring all four strings cleanly while keeping the bass note G♯ clear.
C♯7sus4/G♯ inversion
C♯ 7th suspended 4th is played at the 4th fret as 4 4 4 4: barre your index finger across fret 4.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 4 | 1 (barre) | G♯ (5) |
| 3 (A) | 4 | 1 (barre) | C♯ (1) |
| 2 (D) | 4 | 1 (barre) | F♯ (4) |
| 1 (G) | 4 | 1 (barre) | B (♭7) |
Why it sounds like that
C♯ 7th suspended 4th is built from the formula 1, 4, 5, ♭7. The perfect 4th between C♯ and F♯ creates the suspended sound, while the minor 7th B adds tension. Compare it to C♯ suspended 4th, which omits the minor 7th.
What goes wrong with C♯ 7th suspended 4th?
- Letting the middle finger flatten onto the A string, which deadens the 11th-fret note.
- Pressing the barre too hard in the inversion, causing the strings to buzz.
When to use it
C♯ 7th suspended 4th acts as the V chord in F♯ major, appearing in the I–IV–V–I progression F♯ major–B major–C♯ major–F♯ major. It suits rock and blues bass lines that need a suspended dominant. Compare it to C♯ minor to hear the difference between a suspended dominant and a minor chord.
Changing to and from C♯ 7th suspended 4th
- Sliding the shape down two frets to the 7th fret gives B 7th suspended 4th.
- Sliding the shape up one fret to the 10th fret gives D 7th suspended 4th.
Which voicing to use
The 9th-fret shape keeps C♯ in the bass for a root-position sound. The C♯7sus4/G♯ inversion at the 4th fret puts G♯ in the bass, which softens the chord and works well for a lighter texture.
Other C♯ chords
Common questions
How is C♯ 7th suspended 4th written?
C♯ 7th suspended 4th is written C♯7sus4, and the root is also spelled C# in ASCII. It is also spelled D♭ in enharmonic notation for the same sounding root.
Can C♯ 7th suspended 4th be played with open strings?
No, this chord has no open-string voicing. The lowest position is the 4th-fret inversion, which requires a barre.
What mistake do bassists make with this chord?
They often let the middle finger collapse onto the A string, muting the 11th-fret note. Keep that finger arched to let every string ring.