C7
C Dominant 7th — the engine of harmonic motion — the tritone between its third and seventh drives resolution down a fifth.
The keys
C – E – G – B♭
What's inside C7
| Note | Interval from root | Degree |
|---|---|---|
| C | Root | 1 |
| E | Major 3rd | 3 |
| G | Perfect 5th | 5 |
| B♭ | Minor 7th | b7 |
Inversions
| Position | Keys (low → high) |
|---|---|
| Root position | C4 – E4 – G4 – B♭4 |
| 1st inversion | E4 – G4 – B♭4 – C5 |
| 2nd inversion | G4 – B♭4 – C5 – E5 |
| 3rd inversion | B♭4 – C5 – E5 – G5 |
A working voicing
Split the chord between two hands the way working players do — a solid shell low down, the colour tones up top:
| Hand | Keys |
|---|---|
| Left (shell) | C2 – B♭2 |
| Right (colour) | E4 – G4 |
Where C7 lives
Resolving down a fifth
C7 → F
The defining dominant move: the tritone inside this chord releases onto the chord a fifth below.
In a ii–V–I
Gm7 → C7 → Fmaj7
This chord as the V — the engine of the most-used cadence in music.
Put C7 under your fingers
Hear every voicing, see the keys light up, and drill it in the interactive Chord & Voicing Lab.
Open the Chord & Voicing Lab →