C7(b9) chord on guitar
C7(b9) is the dominant flat ninth chord: C, E, G, Bb and Db (1–3–5–b7–b9). On guitar, the diagram shape is x 3 2 3 2 0, with C in the bass.
On the guitar, six strings give the chord room to breathe — some positions use them all, others ask you to mute the lowest ones. In this C7(b9) voicing the bass is C and the shape runs from fret 2 to 3, ringing 1 open string. Its hollow wooden body gives every chord a warm, natural ring that blooms and fades on its own.
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.