Watch the Dominant 9th online guitar lesson by Fareed Haque from 1-2-3 Bossa Nova
Another very common chord, probably familiar to you already. As we said earlier much of bossa nova guitar is based on chord shapes or grips. Often common grips are used for multiple functions. This is a prime example: C9/G = G minor 6 = E 1/2 diminished. Same shape, different chords depending on where you use it.