C
C7b5
Notes
C · E · Gb · Bb
Intervals
- RootC (1P)
- Major 3rdE (3M)
- Diminished 5thGb (5d)
- Minor 7thBb (7m)
Fretboard
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About
The C7♭5 (C–E–G♭–B♭) lowers the fifth, replacing the stable perfect fifth with a tritone above the root. Combined with the tritone already present between 3rd and ♭7, the chord contains two tritones — making it extremely unstable and dissonant. In jazz, 7♭5 functions as an altered dominant with a particular flavour of harmonic restlessness. The 3rd, ♭7, and ♭5 are all essential; the G♭ is the defining alteration, and omitting it leaves a plain C7. It resolves typically to F or Fm. Compared to standard C7, 7♭5 is considerably more harmonically tense.
Similar chords
Chords sharing two or more notes with this one, ranked by overlap.
Scales containing this chord
- C Whole Tone (deg 1)
- A♭ Whole Tone (deg 3)
- B♭ Diminished (deg 2)
- B♭ Whole Tone (deg 2)
- D Whole Tone (deg 6)
- D♭ Diminished (deg 8)
- D♭ Harmonic Minor (VII)
- D♭ Melodic Minor (VII)
- E Diminished (deg 6)
- E Whole Tone (deg 5)
- F♯ Whole Tone (deg 4)
- G Diminished (deg 4)
- G Melodic Minor (IV)
Scales whose notes include every chord tone. Roman numeral marks the chord root’s position in the scale; dashed badges aren’t linked yet.