In November 2013, a TMZ cameraman greeted Chief Keef as he wandered, blinking, into LAX baggage claim. Keef was being sentenced to rehab, and the TMZ drone flung questions at him in his employer’s house style (lightly mocking, difficult to ignore), about his drug use, his fast driving, his habit of carrying too much cash around. Was he planning to change? Flashing a smile that seems charitable to spare for a paparazzo, Keef responded simply (and unforgettably): "I growed up. I glowed up."

He repeats this ear-sticking phrase, "glowed up", on the first track of his latest mixtape, Sorry 4 the Weight. Dropped last week with a title punning on Lil Wayne’s recent release, the tape feels like an emergence, in a way, from Keef’s wilderness period. After Interscope released Finally Rich, the Chicago rapper underwent serious, uh, glowing pains, during which his already-dark music took a surreal, infernal turn. He uploaded songs to his SoundCloud, like "Wait", that felt too weird to include on any official releases. He taught himself to produce. On Back From the Dead 2 and Nobody, he drowned his voice in processing like someone bent on murdering their personality through technology. It was a fascinating reinvention, forged away from the glare of major labels, in the soup of YouTube and Audiomack plays. It was occasionally indistinguishable from flailing. On Sorry 4 the Weight, he emerges as something new: A calm, poised, self-sufficient auteur, a production machine of Keef Music.

The tracks on Sorry 4 the Weight are credited to simply GGP, or Glo Gang Productions. Individual names are subsumed into the collective, but members include Hurtboy AG, 12 Hunna, DP Beats, and Keef himself. The vagueness of authorship may be intentional, a way of retaining ownership over a house sound. And that sound has settled into something that feels both formally fixed and malleable, a sort of sonic Silly Putty that can be stretched and stamped in any direction. The basic stuff of the sound comes from tinny MIDI patches arguing with each other in squiggly bursts, while drums boom and rattle. The sounds all line up along the same plane, so it all reaches your ear in a trebly tangle of mid-frequencies. It’s both busy and dinky, a hard chunk of sound that separates into a writhing pile of earworms when poked.

Congas and bongos, clattering busily around the edges of the music, are the most noticeable new addition on Sorry 4 the Weight. On "What Up", produced by Keef himself, circular bongos pulse against a snare roll, and Keef weaves a third pattern in between them, so that there are at least six different permutations of rhythms to nod your head to. This is where the sneaky complexity of Keef’s music comes in: He’s a formal innovator, one who finds lots of ways for his muttering vocals to mesh with the contrary moving lines of his music. His cadences have strange emphases everywhere, and the effect is similar to hearing someone clumping around a floor above you wearing a full leg cast. He breaks words up over bars, so that words like "money" get rendered as two molten lumps, "mah" and "nah", strewn across different beats.

These sorts of decisions are often what keep skeptical rap fans at an arm’s length from Keef, but Sorry 4 the Weight is the least abstracted thing he’s released in a long while. His voice is mixed higher and clearer; there is less AutoTune applied to his voice, fewer glottal non-verbal performances. He raps, for bars and bars at a time, in a way that he hasn’t seemed interested in for awhile, and in a way that rap fans who feel reflexively derisive about him probably aren't used to. He has a gift for writing hooks that contain enough jokes, thoughts, and phrases in them that they feel like they could be the whole song, a talent that you can trace back directly to Gucci Mane, and indirectly to 50 Cent before that, who Keef idolizes and namechecks again on an interlude on Sorry.

There are still fleeting moments of the nightmarish, sinking-tarpit sound of his wildest work: On "W.W.Y.D.", over clotted-up synths, Keef’s voice moves like headlights in fog, and his words break down into outbreaks of "Skoot-doo-do". It’s still thrilling to hear, and it makes one wish that wasn’t such a clean partition set between Keef’s verses and his flirtations with the digital void. The loneliness and poetry of "Nobody", say, in which Keef’s wandering, bluesy vocal take may as well be a wah-wah guitar solo for all you can make out of it, is missing. Sorry 4 the Weight is more settled-sounding, a "grown" record from an artist who seems grimly determined to move forward at all costs. "If I'm in my mansion, every day all day, best believe I'm working on something...That's all I need to be happy. Work, work, work myself," he says on the intro to "Ten Toes Down". Maybe once he feels safe in his mansion again, he can invite the chaos back into his studio.