C9 chord
The C dominant ninth chord (abbreviated "C9 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 sometimes omitted from the C9 chord because it's not always possible to play all notes simultaneously.
Name
C dominant ninth chord
Notes
C E G B♭ D
Intervals
1 3 5 ♭7 9
Chord symbol
C9
Type
Pentad (five-note chord)