What I really like about modern RnB music is the way chord progression are used. It's a new approach.
Very few chords are played and they are repeated in a loop. The progression is very ambiguous and unstable. For the listener it means it means hanging in uncertainty. A feeling of something really close without the possibility to catch it or hold it. For musician it means using modes, clever modulations, hiding strong and obvious harmonic functions like the tonic or disguising it as a dominant.
An amazing effect of beautiful endless loop and in my opinion a metaphor for modern life, full of virtual worlds, driven by imagery and illusive branding. A sense that everything has two opposite sides, duality of characters, no clear boundaries between "Good" and "Bad", expect the unexpected.
That's just one of the things that came to my mind while listening to Jazmine Sullivan's "Heaux Tales". But there is more to that album. It's a sonic novel, with great stories, spoken word bits and lyrics.