Though he doesn’t always get the credit he deserves, few artists have done as much to shape the sound of West Coast hip-hop as DJ Quik. A low-key and effortlessly fun collaboration with the young Compton rapper Problem, Rosecrans honors G-funk traditions while also giving them subtle twists, like the jazzy vamp of “A New Nite / Rosecrans Grove,” or the airy, almost collage-like samples of “You Are Everything,” among guest spots from The Game and Wiz Khalifa. Never content with sitting still, Quik cruises on.