Listen to Chief Keef Feat. Sean Kingston, “Murda Mook” (Prod. by Metro Boomin)

Over the past month or so, and most notable during his guest verse on Mac Miller's album, Chief Keef's usual slur has disappeared and his flow has sharpened considerably. On "Murda Mook," Keef keeps up the good work over menacing production from everybody's new favorite man behind the boards, Metro Boomin. Keef is urgent with his delivery, enunciating every word and hitting every 808 from Metro hard. Paying homage to New York battle rapper Murda Mook, Chief creates a new slang term by incorporating the MC's moniker. Sean Kingston hops on the track at the end and shows a darker side than we're used to. While it's a bit off-putting to hear Kingston rap about popping Xanax, his appearance fits perfectly with Keef's aggressiveness and Metro's production. Check it out below