Atmospheric but still banging, Covert Coup is the debut collaboration from a duo who’ve evolved unpredictably: Curren$y, the No Limit trenchman-turned-stoner-rap auteur, and The Alchemist, whose eerie Y2K-era boom-bap beats became increasingly abstracted. The Alchemist’s production is, at once, restless and dreamlike on woozy sketches like “Smoke Break” and “Success Is My Cologne,” and Curren$y’s rhymes are loose but still lucid. Check the sudden beat switches on “The Type,” making way for a rugged verse from Mobb Deep’s Prodigy.