Since he first appeared on the radar with “Tupac Back,” it’s been hard to think of him doing much else than the kind of super-hyped shouting that is now his calling card. It’s no accident that Meek Mill has become, with a couple of years of singles and high-profile features under his belt, fairly predictable. The “untouchable” Maybach Music Group is a juggernaut now, but over the years it has achieved its dominance through more than a little shrewd legerdemain, and part of that master plan has been treating Meek Mill like a utility player, rather than a star in his own right. Since Dreams and Nightmares is Meek Mill’s major label debut -- his first opportunity to show who and what he is -- it is worth it to first set out the story of Maybach Music as context for both this artist and his album.