C7(b9) chord: dominant flat ninth
C7(b9) is the dominant flat ninth chord on C: C, E, G, Bb and Db (1–3–5–b7–b9). C7(b9) stacks the root C, the major third E, the perfect fifth G, the minor seventh Bb and the minor ninth Db. The 7(b9) is a dramatic dominant.
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.
The minor ninth intensifies the resolution, especially when the target chord is minor.
The same chord on all four instruments
Where to use it
A dominant that resolves to a minor chord.
Part of the Altered dominants family.