If you are a hip-hop fan who considers a rapper’s talent as directly proportional to the size of his or her vocabulary, and for whom the phrase “back in the day” is always accompanied by a wistful sigh, prepare for your worst nightmare in zeitgeist-surfing 19-year-old Atlanta rapper Lil Yachty. There are certainly some idiotic moments on his 21-song debut LP. On one chorus, he just says “Harley” over and over again, while, on Better, presumably floundering for a word that rhymes with “whatever” and “clever”, he shoehorns in the name Trevor. His mum will be charmed by the song dedicated to her, less so by him telling a female house guest, on DM Freestyle, that “there’s piss all in the bathroom, bitch go clean it up”.

There is a fundamental misunderstanding of woodwind instrumentation when he says another young lady can “blow that dick like a cello”. There are precious few punchlines and still fewer original images – just a zoetrope of sex, money and Xanax.

And yet this is an instinctively catchy and frequently startling record. Yachty draws on some clear influences – the arrhythmic streams of teen consciousness of Lil B and Soulja Boy, the radical, autotuned solipsism of Kanye West, the soapbox declarations of Young Thug – and carbonates them into brilliant outsider pop.

The waltz-time trap flow on X-Men and Peek a Boo connects satisfyingly, but these straightforward tracks are relatively thin on the ground. The rest are blithe singsong affairs that Ralph Wiggum might have made if he had grown up on purple drank; fascinating, meandering ballads that veer towards Dean Blunt territory; and mid-tempo R&B numbers such as the superb Bring It Back, which sounds like a sentient Amazon Echo singing Drake’s Hold On We’re Going Home drunk outside your window at 3am. Meanwhile, the perfect chorus of Priorities – “My priorities are fucked/ My priorities are fucked” – will surely become an anthem for Tinder-swiping, debt-racking millennials everywhere.

Like fellow pop-rappers Rae Sremmurd, Yachty will often use a single melody for the verse and chorus, thus creating a new, disturbing kind of catchiness, a hook that digs into your cortex with such purchase that at least one part of your subconscious is singing it at all times. His freewheeling scansion, meanwhile, stops it being monolithic or boring. Like the cupcake frosting on which Yachty almost certainly lives, you couldn’t eat it exclusively, but the nerve-jangling, even psychedelic sweetness is a bold, new flavour in rap, one that shows the genre is more creatively varied than ever.