The C-sharp dominant ninth chord (abbreviated "C#9 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-sharp dominant seventh chord.

In practice, the fifth (G) is sometimes omitted from the C#9 chord because it's not always possible to play all notes simultaneously.

Name
C-sharp dominant ninth chord
Notes
C E G B D
Intervals
1 3 5 7 9
Chord symbol
C9
Type
pentad (five-note chord)

C#9 chord on piano

C#9 chord on guitar

C#9 chord on ukulele

C#9 chord on the staff