Moreover, what is a C9 chord on guitar?
The C9 chord is composed of the notes C, E, G, Bb, and D. Ninth chords are a family of extended chords, created by adding the major (or minor) ninth to a seventh chord.
Consequently, what key is Cissy Strut in? Cissy Strut is written in the key of Cm.
Open Key notation: 10m.