Wiz Khalifa's modus operandi has always been simple: rap about smoking loads of weed and create earwormy tracks built on repetitive hooks. He perfected the combination on his 2011 hit, Black and Yellow, an ode to his favourite colours and the Pittsburgh Steelers. On Blacc Hollywood, he's at it again. We Dem Boyz was online months ago, and its simple call-and-response chorus and booming kick-drum was enough to start building hype. The template is repeated on KK, with help from former Three 6 Mafia member Juicy J and his older brother, Project Pat, while there's posterior-praising on Ass Drop and a song, Raw, about driving a car while smoking weed. But unlike, say, Juicy J or Gucci Mane, whose tales of trapping (drug-dealing) sound convincing and at times terrifying, Khalifa's attempts to toughen up feel like hot air. He's undone further by his rap-crooning on Promises, as cringe-inducing as it is bland and, in contrast to We Dem Boyz, was panned when it came out in the lead-up to Blacc Hollywood. He's in similar territory on House in the Hills, a Drakean bit of reflective emo-rap about west-coast living that goes nowhere, despite a turn from the talented Curren$y. Khalifa sounds at his best when he sticks to his formula, instead of trying to tap into the (increasingly lucrative) rapper-with-a-heart-of-gold market.