How to play the C Dominant 7th chord on guitar
C7 adds one finger to the C shape and instantly turns it bluesy. In a twelve-bar blues in F it is the chord that sets up the change, and it is the cheapest demonstration that one note can change a chord's whole function.
C Dominant 7th is a dominant seventh: the C triad with a flattened seventh on top — C, E, G, A#. That added note is what gives it its bluesy, unfinished pull.
Finger it one string at a time
- low E string: don't play it.
- A string: fret 3 with your ring finger.
- D string: fret 2 with your middle finger.
- G string: fret 3 with your pinky.
- B string: fret 1 with your index finger.
- high E string: play it open.
Add your pinky to the standard C major chord. Very common in blues.
What makes this shape awkward
- The shape spans 3 frets, so your hand has to stretch rather than sit in one position. Bring your thumb down behind the neck to open the gap between your fingers.
- 1 string stays silent, so your strumming hand has to start on the right string. Aim the pick rather than sweeping all six.
Where you'll use it
C7 appears in 2 of the play-along progressions in RiffRoute. These are the actual sequences it sits in:
- Amber Turnaround (Jazz Standard, 120 BPM) —
Am → D7 → G7 → C7 - Windfall Picking (Acoustic Folk, 90 BPM) —
C → C7 → Am → Asus2 → Asus4 → Am
Chords it's usually played with
In the progressions that use C7, these turn up alongside it most often — learning them together is more useful than learning C7 alone.
If this one is still too hard
C Dominant 7th is an intermediate shape. These beginner chords use a related root or quality and are worth getting clean first:
Hear it and check yourself
Reading a diagram only gets you so far — the part that decides whether C7 sounds right is whether every string rings cleanly. RiffRoute plays the chord back, listens while you strum it, and tells you which string is buzzing.