The C-sharp half-diminished seventh chord (abbreviated "C#m7(b5) chord") is a four-note chord consisting of the notes C, E, G, and B. The chord is formed by lowering the fifth of a C-sharp minor seventh chord a half step.

Name
C-sharp half-diminished seventh chord
Synonyms
C-sharp half-diminished chord C-sharp minor seventh flat five chord
Notes
C E G B
Intervals
1 3 5 7
Chord symbol
Cm7(b5)
Alternative symbols
Cø Cø7 Cm7b5 C7(b5) Cmi7(b5) Cmin7(b5)
Type
Tetrad (four-note chord)

C#m7(b5) chord on piano

C#m7(b5) chord on guitar

C#m7(b5) chord on ukulele

C#m7(b5) chord on the staff