IN THE MID-TO-LATE '00s, Lil Wayne was the most creative and prolific popular force in rap. He did little, it seemed, aside from take drugs and record.

That double cup, since discarded, has been picked up by Atlanta rapper Young Thug. And where Weezy offered unmatched lyrical flights of fancy, untethered metaphors, and slippery turns of phrase, Thug's innovations are sonic and melodic. He's far out, so comfortable in deep space that it's often difficult to tell what the 23-year-old ATLien is saying—if he's even using words at all.

Sometimes that's because Thug is buried in vocal effects. Other times it's because he's using his mouth to make sounds. He mumbles, mutters, squawks, and croaks. He warbles around notes and never finds them. And, of course, he raps too—as the adage goes, you've got to know the rules before you can break them.

I played Young Thug for a friend, a fan of hip-hop and deep free-jazz exploration. I cued up "Lifestyle," a leftfield hit. Words are mangled, dripping into gibberish, indiscernible syllables pushed and pulled. "What is this, dude?" my friend shot back, scratching his head.

Indeed, Thugga's is an emergent vocabulary, and it may take a little getting used to. As such, I've created a playlist in service of giving him a more proper introduction, and also to help cut through the clutter—after releasing some six mixtapes in the past year alone, there's plenty of gristle. And while this primer is neither comprehensive nor an absolute "best of," it should show some range, from the croaks of conspicuous consumption to the croons of heartbreak. Indeed, Young Thug is a rounded, feeling human being, despite what all the alien utterances might lead you to believe.

"Picacho" [Young Thug feat. Maceo]—My introduction to Thug came in 2013 via this glistening, upbeat banger. The chorus only suggests how weird he'd get in subsequent years.

"Florida Water" [Young Thug & Bloody Jay]—On the Black Portland mixtape (whose cover features Blazers colors and logo, and whose title has never been sufficiently explained), Thug wrings out the song's titular phrase in every direction, tweaking pronunciation for an oozing hook.

"I Know There's Gonna Be (Good Times)" [Jamie XX feat. Young Thug & Popcaan]—Jamie XX's beat, a lifting smash of a scratchy, warm, soul sample from the Persuasions, is a largely different platform than Thug's usual minor-key trap minimalism. But the texture-shifting left turn works.

"Destroyed" [Young Thug feat. Kevin Gates, Birdman, & MPA Duke]—Six minutes long, this song is brutally sad. It's one of a slew of Thug's leaked material that focuses on a breakup. Lines like "Try to put my li'l baby in her she had an abortion/Even though we love each other we can't show emotions" are indelible, and the following boilerplate gangster talk can't erase them.

"Who's on Top" [Young Thug, Birdman, & Rich Homie Quan feat. MPA Duke & MPA Wicced]—A sharp, dance-y electro beat that Thug just shreds. Up against Rich Homie Quan and Birdman, Thug reigns.

"Blood" [Dej Loaf feat. Young Thug & Birdman]—I'll take any reason to slide Dej Loaf into conversation. Her smooth, cool delivery is every bit as sui generis as Thug's.

"Treasure" [Young Thug feat. Zuse]—In rapid-fire flow, Thugga hilariously wonders of pirates: "How the hell a nigga leave a treasure?"

"Drinking Lean Is Amazing" [Young Thug]—Formless and playful, the title of this leaked track says it all.

"Constantly Hating" [Young Thug feat. Birdman]—Thug swings above a loose, lilting, mellow, and distant beat. Even though the track features Birdman, Thug's contribution makes it worth replaying, which is really saying something.

"Guarantee" [Young Thug feat. Ayanis]—Another of the dark, hurting leaked tracks, this features Ayanis' doubled singing over Thug's, such an effective, affecting combination it ought to be revisited.

"4 Eva Bloody" [Young Thug & Blood Jay]—Rarely has a chorus about gang affiliation been this huge and hummable. Likewise, the beat is over-the-top, glittering schmaltz.

"Take Kare" [Rich Gang feat. Young Thug & Lil Wayne]—Regardless of politics and beef, this one's solid. While Thug outshines the former master, he energizes Wayne, who gives one of his most inspired verses in recent memory.