C13#11 chord for piano presented by keyboard diagrams.
Explanation: The C13#11 alter the C13 by the change of one note. The C thirteenth sharp eleventh 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 C13(#11) or C13+11.
Theory: Compared to C13 the eleventh tone in the chord is sharpenedThe tone is one half step higher.
Notes: C - E - G - Bb - D - F# - A