C7 guitar chord
Root, third and seventh: the guide tones fix the quality, so the fifth is dropped. That is what leaves a string free, so pick a tension to put on top.
- Tap a note to hear it
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- Fingers, notes or intervals
- Play the chord
About C7 — shell voicings
C7 is C, E, G and Bb — C with the flat seventh added on top.
It sounds restless and pointed at something. The third and the flat seventh are a tritone apart and each moves by a semitone into the next chord; that is the engine of a cadence, and the whole vocabulary of the blues.
C7 notes and formula
| C | E | G | Bb |
|---|---|---|---|
| 1 | 3 | 5 | ♭7 |
Dominant — it points a fifth down.
Also written Cdom7 or C dominant 7. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play C7
Root, third and seventh. The third and seventh, the guide tones, are what make the chord major, minor or dominant, so the fifth can go: it says nothing the symbol needs.
Three notes means a spare string, which is the real point. Put a tension on it.
C7 has 5 of them, on the low-middle three, the bottom three strings, strings 5-3-2 and strings 6-4-3, from the 2nd fret up to the 14th — all in one inversion, so the bass note never moves. The one to learn first is the C shape at the 2nd fret, which is the easiest grip here.
Start with x32310 — no barre and 1 open string. 1 of the 7 shapes here sits in open position. 4 of the 7 need a barre. Together they cover the neck from the 1st fret to the 15th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x32310 | open position | C, root position | E | 1 open string |
| x35353 | 3rd fret | C, root position | G | barred |
| xx5556 | 5th fret | G, 2nd inversion | Bb | barred |
| 875556 | 5th fret | C, root position | Bb | barred |
| 8-10-8-9-8-8 | 8th fret | C, root position | C | barred |
| x-x-10-12-11-12 | 10th fret | C, root position | E | all fretted |
| x-15-14-15-13-x | 13th fret | C, root position | C | all fretted |
The same notes rebuilt from scratch give 15 drop 2, 10 drop 3 and 6 open string voicings, each on its own page.
Tensions. A shell of C7, root, third and seventh, leaves a string free, and the tones that belong over it are the b9 (Db), the 9 (D), the #9 (D#), the #11 (F#), the b13 (Ab) and the 13 (A).
How to use C7
C7 is the V of F, and that is where it goes if it goes anywhere: the third and the flat seventh are a tritone apart, and both resolve by a semitone into F.
Voice by voice, C7 → F. 2 voices move by a semitone, and one note is common to both chords.
| In C7 | Moves | In F |
|---|---|---|
| C, the root | stays where it is | C, the fifth |
| E, the major third | rises a semitone | F, the root |
| G, the fifth | falls a whole tone | F, the root |
| Bb, the flat seventh | falls a semitone | A, the major third |
In which keys. Every note of C7 belongs to D minor (the ♭VII) and F major (the V, the dominant).
What to play over C7
Every note of C7 is in C mixolydian, C lydian dominant and C half-whole diminished.
Chords near C7
Change one note of C7 and you have C (drop the flat seventh), Cmaj7 (the flat seventh becomes a major seventh), Cm7 (the major third becomes a minor third), Cadd9 (the flat seventh becomes a ninth), C6 (the flat seventh becomes a sixth) or C7sus4 (the major third becomes a fourth).
C7 is a dominant chord — root, major third, fifth, minor seventh. Dominant seventh chords on every root.
On C7’s sound and use this page follows Edward Aldwell & Carl Schachter, Harmony and Voice Leading (Schirmer / Cengage, 4th ed., 2011). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.