“Take over the world when I’m on my Donald Trump shit. / Look at all this money, / ain’t that some shit,” brags 20-year-old Pittsburgh MC Mac Miller on a tune called “Donald Trump.” The video’s gotten more than 25 million clicks and Mr. Trump himself predicted that Miller was “the next Eminem.” But aside from Miller being a white hip-hop artist, the comparison’s vacuous. On mix-tapes like K.I.D.S. (Kickin’ Incredibly Dope Shit) and Best Day Ever, Miller spits about partying and wild times, sorority girls, and freshman-year shenanigans with a vibe that’s lighthearted and optimistic—nothing like Eminem’s dark, twisted vision. His debut album, Blue Slide Park, is out now on Rostrum, the label-home of fellow Pittsburgh rapper Wiz Khalifa.