At its most shimmering, the long-in-the-works solo debut from the former En Vogue and Lucy Pearl diva incorporates the best of both acts. The R&B effortlessly shoop-shoops with simmering beats and the occasional raw guitar (”Set It Off” should be a hit), and Robinson’s stance is more aggressive, as she dresses down scrubs and asks another to stick around for the sake of their baby. But at its limpest, Dawn is merely a thinking man’s Mariah Carey album. B