The C9 sus 4 chord (C9 suspended 4, or Bb/C) contains the notes C, F, G, Bb and D. It can be thought of as a C9 chord with a 4th (instead of a 3rd) or a Bb chord with a C in the bass.

10 Ways To Play The C9 Sus 4 chord

If you’ve come to this page just to view some chord diagrams for C9 Sus 4 (Bb/C), here they are.

C9 Sus 4 Chord 10 Shapes