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C 7th sharp 5 chord on bass (C7♯5)
Also called or written C7♯5, C or C Dominant 7th ♯5
C 7th sharp 5 contains C, E, G♯, and B♭. The default voicing at the 4th fret uses a wide four-finger stretch.
How it is built
Formula 1, 3, ♯5, ♭7
How do you play a C 7th sharp 5 chord on bass?
C 7th sharp 5 is played at the 2nd fret as 4 3 2 3: pinky finger on the E string at fret 4, middle finger on the A string at fret 3, index finger on the D string at fret 2 and ring finger on the G string at fret 3.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 4 | 4 | G♯ (♯5) |
| 3 (A) | 3 | 2 | C (1) |
| 2 (D) | 2 | 1 | E (3) |
| 1 (G) | 3 | 3 | B♭ (♭7) |
AdvancedThe pinky must reach the 4th fret on the E string while the index holds the 2nd fret on the D string.
C7♯5/B♭ inversion
C 7th sharp 5 is played at the 5th fret as 6 7 6 5: middle finger on the E string at fret 6, pinky finger on the A string at fret 7, ring finger on the D string at fret 6 and index finger on the G string at fret 5.
Full note and interval breakdown
| String | Fret | Finger | Note |
|---|---|---|---|
| 4 (E) | 6 | 2 | B♭ (♭7) |
| 3 (A) | 7 | 4 | E (3) |
| 2 (D) | 6 | 3 | G♯ (♯5) |
| 1 (G) | 5 | 1 | C (1) |
Why it sounds like that
C 7th sharp 5 is built from the formula 1, 3, ♯5, ♭7. The augmented 5th, G♯, gives the chord its bright, tense sound. Compare it to C 7th, which has a perfect 5th.
What goes wrong with C 7th sharp 5?
- Letting the pinky collapse and mute the A string.
- Pressing the index finger too flat and buzzing the D string.
- Striking the open E string instead of the 4th fret.
When to use it
C 7th sharp 5 functions as a dominant chord in C major progressions, such as C–F–G, the I–IV–V. It suits jazz, blues, and funk lines that need a raised 5th. It pairs well with C major and C 7th.
Changing to and from C 7th sharp 5
- Sliding the shape down one fret to the 1st fret gives B 7th sharp 5. Keep the finger spacing identical while shifting.
- Move to C 7th by lowering the D string from the 2nd fret to the 1st fret; the other fingers stay in place.
Which voicing to use
The G♯ inversion puts the augmented 5th in the bass, creating a tense, unstable sound. The B♭ inversion has the ♭7 in the bass and is higher on the neck. Choose the G♯ inversion for a more dissonant line.
Other C chords
Common questions
How is C 7th sharp 5 written?
C 7th sharp 5 is written as C7♯5 or C7+5. The symbol C7♯5 is the most common.
What is the difference between C 7th sharp 5 and C augmented?
C 7th sharp 5 adds a minor 7th, B♭, to the augmented triad C–E–G♯. C augmented has only the root, major 3rd, and augmented 5th. The 7th makes the chord dominant and more dissonant.
Can C 7th sharp 5 be used as a passing chord?
C 7th sharp 5 works as a passing chord between C 7th and C 9th. Its raised 5th creates tension that resolves to the next chord. Use it briefly on a weak beat.