Gary Clark Jr definitely ain't your classic blues artist, lots of soul, r&b and even hard rock elements in his music too, I love the variety in Blak and Blu.
I thought it's a pretty good album, not very easy to listen to, but it has depth, looking forward to the new Queens of Stone Age album where Grohl and Homme are working together again. My favorite track on Sound City was the Corey Taylor (Slipknot, Stone Sour) one.