C 7th flat 5 chord on guitar (C7♭5)

Also called or written C7♭5, C, C Dominant 7th Flat 5 or C 7th ♭5

C 7th flat 5 is built from C, E, G♭, and B♭. The 3rd-fret voicing mutes both E strings, leaving a compact four-string shape.

3frCG♭B♭EEADGBE
Positions on the neck1 of 5
Practice C 7th flat 5 chord

How it is built

CRootEMajor thirdG♭Diminished fifthB♭Minor seventh

Formula 1, 3, ♭5, ♭7

Inversions

How do you play a C 7th flat 5 chord on guitar?

C 7th flat 5 is played at the 3rd fret as × 3 4 3 5 ×: index finger on the A string at fret 3, ring finger on the D string at fret 4, middle finger on the G string at fret 3 and pinky finger on the B string at fret 5. The low E and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)31C (1)
4 (D)43G♭ (♭5)
3 (G)32B♭ (♭7)
2 (B)54E (3)
1 (e)muted

AdvancedThe 3rd-fret voicing requires muting both E strings while fretting the A, D, G, and B strings cleanly.

7th fret

C 7th flat 5 is played at the 7th fret as 8 7 8 9 7 ×: barre your index finger across fret 7, middle finger on the low E string at fret 8, ring finger on the D string at fret 8 and pinky finger on the G string at fret 9. The high e string stays muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)82C (1)
5 (A)71 (barre)E (3)
4 (D)83B♭ (♭7)
3 (G)94E (3)
2 (B)71 (barre)G♭ (♭5)
1 (e)muted

8th fret

C 7th flat 5 is played at the 8th fret as 8 9 8 9 × ×: index finger on the low E string at fret 8, ring finger on the A string at fret 9, middle finger on the D string at fret 8 and pinky finger on the G string at fret 9. The B and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)81C (1)
5 (A)93G♭ (♭5)
4 (D)82B♭ (♭7)
3 (G)94E (3)
2 (B)muted
1 (e)muted

10th fret

C 7th flat 5 is played at the 10th fret as × × 10 11 11 12: index finger on the D string at fret 10, middle finger on the G string at fret 11, ring finger on the B string at fret 11 and pinky finger on the high e string at fret 12. The low E and A strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)muted
4 (D)101C (1)
3 (G)112G♭ (♭5)
2 (B)113B♭ (♭7)
1 (e)124E (3)

C7♭5/E inversion

C 7th flat 5 is played at the 1st fret as × × 2 3 1 2: middle finger on the D string at fret 2, pinky finger on the G string at fret 3, index finger on the B string at fret 1 and ring finger on the high e string at fret 2. The low E and A strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)muted
4 (D)22E (3)
3 (G)34B♭ (♭7)
2 (B)11C (1)
1 (e)23G♭ (♭5)

Why it sounds like that

C 7th flat 5 stacks a major 3rd, a diminished 5th, and a minor 7th. The diminished 5th between C and G♭ defines the chord. Compare it to C 7th, which uses G instead of G♭.

What goes wrong with C 7th flat 5?

  • Letting the low E string ring out and overpower the C bass note.
  • Not muting the high E string, which adds an unwanted E note.
  • Flattening the pinky and muting the B string.

When to use it

C 7th flat 5 works as a dominant substitute in F major, resolving to F major. Its tense sound fits jazz and blues. Try it before F major or C 7th.

Changing to and from C 7th flat 5

  • From the 3rd-fret shape, move your index finger to the 2nd fret of the A string and your ring finger to the 3rd fret of the D string for B 7th flat 5.
  • Slide the 3rd-fret shape up one fret to the 4th fret to get C♯ 7th flat 5.

Which voicing to use

The 3rd-fret voicing is the most compact, but the 7th-fret barre version offers a fuller sound with the root on the low E. The C7♭5/E inversion places E in the bass for a different color.

Other C chords

Common questions

Why are both E strings muted in C 7th flat 5?

The open E strings are chord tones, but they are muted to keep the C bass note and the intended voicing. Muting them prevents the chord from becoming too dense.

What is the difference between C 7th flat 5 and C 7th?

C 7th flat 5 lowers the perfect 5th of C 7th by one semitone to G♭. That creates a diminished 5th interval and a more dissonant sound.

How does C 7th flat 5 resolve?

C 7th flat 5 typically resolves to F major. The tritone between C and G♭ pulls strongly toward the F major chord.