C7b5 guitar chord
The standard grips this chord is usually shown with.
- Tap a note to hear it
- Arrows change position
- Fingers, notes or intervals
- Play the chord
About C7b5 — 1st inversion
C7b5 is C, E, Gb and Bb — C7 with the fifth lowered a semitone.
It sounds symmetrical and slightly unreal. The same four notes spell a 7♭5 a tritone away, which is exactly why one can stand in for the other.
Altered dominant — and the chord that makes the tritone substitution work.
C7b5 notes and formula
| C | E | Gb | Bb |
|---|---|---|---|
| 1 | 3 | ♭5 | ♭7 |
Also written C7(b5), C7-5 or C7♭5. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play C7b5
C7b5 in 1st inversion puts E in the bass instead of C, the 3rd of the chord. The notes are the same; what changes is what the bass line does, which is most of why you would reach for it — it lets the lowest voice move by step where the root would have jumped.
One of C7b5’s 5 common shapes does this:xx2312
Play C7b5 as a shell — root, third and seventh — and the spare string takes the b9 (Db), the 9 (D), the #9 (D#), the b13 (Ab) or the 13 (A).
All 5 common shapes as fret numbers, lowest string first. Hover or tap one to see it drawn.
- x12312, 1st fret, Bb, 3rd inversion, top note Gb, all fretted
- xx2312, 1st fret, E, 1st inversion, top note Gb, all fretted
- x3435x, 3rd fret, C, root position, top note E, all fretted
- 8x8970, 7th fret, C, root position, top note Gb, 1 open string
- x-x-10-11-11-12, 10th fret, C, root position, top note E, all fretted
How to use C7b5
C7b5 is a dominant with its tension raised, so it still points at F — harder than a plain seventh does, because the altered tones sit a semitone from where they are going.
In a phrase:Gm7→C7b5→Fmaj7— the ii–V–I of F.
Voice by voice, C7b5 → F. 3 voices move by a semitone, and one note is common to both chords.
| In C7b5 | Moves | In F |
|---|---|---|
| C, the root | stays where it is | C, the fifth |
| E, the major third | rises a semitone | F, the root |
| Gb, the flat fifth | falls a semitone | F, the root |
| Bb, the flat seventh | falls a semitone | A, the major third |
What to play over C7b5
Every note of C7b5 is in C whole tone, C lydian dominant, C altered and C half-whole diminished.
Chords near C7b5
Change one note of C7b5 and you have Cmaj7b5 (the flat seventh becomes the major seventh), Cm7b5 (the major third becomes the minor third), C7 (the flat fifth becomes the fifth), C7/G (the flat fifth becomes the fifth), Caug7 (the flat fifth becomes the sharp fifth) or C9b5 (add the ninth).
C7b5 is an altered chord — a dominant seventh with its fifth or ninth moved. Altered dominant chords on every root.
The common shapes and the derived voicings come from different places, and both are explained in how this site is built.