C#7(b9) chord
The C-sharp dominant minor ninth chord (abbreviated "C#7(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-sharp dominant seventh chord.
In practice, the fifth (G♯) is often omitted from the C#7(b9) chord because it's not always possible to play all notes simultaneously.
Name
C-sharp dominant minor ninth chord
Notes
C♯ E♯ G♯ B D
Intervals
1 3 5 ♭7 ♭9
Chord symbol
C♯7(b9)
Alternative symbol
C♯7b9
Type
pentad (five-note chord)