C#13b9 chord
C#13b9 chord for piano presented by keyboard diagrams.
Explanation: The C#13b9 alter the C#13 by the change of one note. The C sharp thirteenth flat ninth is a seven-note chord, but due to practical circumstances, one or more notes (the fifth primarily) are omitted. The chord name can also be written as C#13(#b) or C#13-9.
Theory: Compared to C#13 the ninth tone in the chord is flattenedThe tone is one half step lower.
C#13b9

Notes: C# - F - G# - B - D - F# - A# / C# - E# - G# - B - D - F# - A#
C13b9 chord ‹ Previous • Next › D13b9 chord
C#13#11 polychord
Explanation: The image below shows a polychord version of the C#13#11. The chord is played in two parts with both hands.

Polychord C#7 (LH), D# (RH)