C 7th flat 5 chord on ukulele (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 5th fret shape stacks three fingers in a row before the pinky reaches fret 7.

5frCG♭B♭EGCEA
Positions on the neck1 of 3
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 ukulele?

C 7th flat 5 is played at the 5th fret as 5 6 6 7: index finger on the G string at fret 5, middle finger on the C string at fret 6, ring finger on the E string at fret 6 and pinky finger on the A string at fret 7.

Full note and interval breakdown
StringFretFingerNote
4 (G)51C (1)
3 (C)62G♭ (♭5)
2 (E)63B♭ (♭7)
1 (A)74E (3)

AdvancedThe pinky must reach fret 7 cleanly while the ring finger holds fret 6 on the E string.

C7♭5/B♭ inversion

C 7th flat 5 is played at the 8th fret as 9 10 8 9: middle finger on the G string at fret 9, pinky finger on the C string at fret 10, index finger on the E string at fret 8 and ring finger on the A string at fret 9.

Full note and interval breakdown
StringFretFingerNote
4 (G)92E (3)
3 (C)104B♭ (♭7)
2 (E)81C (1)
1 (A)93G♭ (♭5)

C7♭5/E inversion

C 7th flat 5 is played at the 2nd fret as 3 4 2 3: middle finger on the G string at fret 3, pinky finger on the C string at fret 4, index finger on the E string at fret 2 and ring finger on the A string at fret 3.

Full note and interval breakdown
StringFretFingerNote
4 (G)32B♭ (♭7)
3 (C)44E (3)
2 (E)21G♭ (♭5)
1 (A)33C (1)

Why it sounds like that

C 7th flat 5 uses the formula 1, 3, ♭5, ♭7. The diminished 5th between C and G♭ gives the chord its tense color. Compare it to C 7th, which raises that G♭ to G.

What goes wrong with C 7th flat 5?

  • Letting the pinky flatten onto the A string, which buzzes the note.
  • Pressing the ring finger too far across, deadening the C string.
  • Strumming before the middle finger is fully seated on the C string.

When to use it

C 7th flat 5 works as a tense dominant in C major, especially moving to C major or C 5th. Its altered fifth suits jazz and funk lines where a plain C 7th sounds too settled.

Changing to and from C 7th flat 5

  • Sliding the shape down two frets to the 3rd fret gives B♭ 7th flat 5.
  • Sliding the shape up one fret to the 6th fret gives C♯ 7th flat 5.

Which voicing to use

The 5th fret position keeps C in the bass for a root-position sound. The C7♭5/E inversion at the 9th fret puts the major third in the bass, while the C7♭5/B♭ inversion at the 3rd fret emphasizes the ♭7.

Other C chords

Common questions

How is C 7th flat 5 written?

C 7th flat 5 is written as C7♭5 or C. The symbol C7♭5 is the most common.

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

C 7th flat 5 lowers the fifth from G to G♭, creating a diminished fifth. C 7th keeps the perfect fifth G.

Why does C 7th flat 5 sound unstable?

The diminished fifth between C and G♭ is a tritone, which wants to resolve. This tension makes the chord useful before a tonic.