Aiming to capitalize on “Just a Dream,” his biggest hit in a half-decade, Missouri’s favorite rapper ends his sixth album with another soft-rock-tinged ballad — “Nothing Without Her,” about taming a bad girl. On his way there, he essays a few fashionably global-sounding electro-club tracks, including an Auto-Tuned one with T-Pain and Akon, and at least four numbers where he swipes guys’ girlfriends. Keri Hilson and Kelly Rowland help him stretch out; Plies, Yo Gotti and T.I. add muscle. But the strut swings most distinctively in “1000 Stacks,” where a Biggie sample inspires Nelly to approximate the country grammar he came up on.