Mariah Carey has always been smart about landing the right collaborators at the right time -- from Boyz II Men to Jay-Z to, yes, Nicki Minaj. For her new single "#Beautiful" (Island Def Jam), she nabs Miguel to co-write and co-produce with her, feeding into the alt-R&B vibe that Miguel and Bruno Mars are currently riding. Despite the awkward title, "#Beautiful" is sleek and timely, floating by on breathy vocals and subdued, but still funky, guitars. Oh, baby, baby, they belong together.