C7(b9) chord on electric guitar
C7(b9) is the dominant flat ninth chord: C, E, G, Bb and Db (1–3–5–b7–b9). On electric guitar, the diagram shape is x 3 2 3 2 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(b9) voicing the bass is C and the shape runs from fret 2 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.
Notes and formula of C7(b9)
Notes in C7(b9): C – E – G – Bb – DbFormula: 1 – 3 – 5 – b7 – b9In 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
A dominant that resolves to a minor chord.
See also
Part of the Altered dominants family.