C#m9 chord

The C-sharp minor ninth chord (abbreviated "C#m9 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 minor seventh chord.

In practice, the fifth (G♯) is sometimes omitted from the C#m9 chord because it's not always possible to play all notes simultaneously.