The C dominant minor ninth chord (abbreviated "C7(b9) chord") is a five-note chord consisting of the notes C, E, G, B, and D. The chord is formed by adding a major ninth to a C dominant seventh chord.

In practice, the fifth (G) is often omitted from the C7(b9) chord because it's not always possible to play all notes simultaneously.

Name
C dominant minor ninth chord
Notes
C E G B D
Intervals
1 3 5 7 9
Chord symbol
C7(b9)
Alternative symbol
C7b9
Type
Pentad (five-note chord)

C7(b9) chord on piano

C7(b9) chord on guitar

C7(b9) chord on ukulele

C7(b9) chord on the staff