Dominant seventh chord (7) on electric guitar
C7 is the dominant seventh chord: C, E, G and Bb (1–3–5–b7). On electric guitar, the diagram shape is x 3 2 3 1 0, with C in the bass.
On the electric guitar a chord needs only a few clear notes — the amp sustains them and fills the space, so you mute the strings you are not playing and let the tone carry the rest. In this C7 voicing the bass is C and the shape runs from fret 1 to 3, ringing 1 open string. Plugged into an amp, each chord sustains for as long as you hold it, and the tone — clean or driven — shapes the whole sound.
C7 on electric guitar: shapes and notes →
Notes and formula of C7
Notes in C7: C – E – G – BbFormula: 1 – 3 – 5 – b7In the formula, the numbers count steps of the major scale starting from the note that names the chord; "b" lowers a half step, "#" raises one — and a slash names the bass note.
Where to use it
Dominant, blues and any point of strong resolution.
See also
Part of the Sevenths family.