Listening now to Finally Rich, Chief Keef’s capstone 2012 release and only album with Interscope, it’s striking how easily the hits seemed to come to the then–17-year-old star. Even its unheralded album tracks hit a sweet spot of purposeful insouciance that promised a career in the spotlight. With songs selected and sequenced largely by Young Chop, Finally Rich is a creative success (if only a modest commercial one) because it sells Chief Keef as a hitmaker. In the pre-Internet industry, perhaps that's just what he would be. But today his interests lie elsewhere, and his path since has been a defiant refutation of any direction but his own.

To make a case for Chief Keef’s more recent music is to wander into a catch–22. Though short, defensive explanations ("he’s got good hooks," "it’s just turn-up music") are tempting, they undersell his breadth; any lengthy defense is dismissed out of hand for overthinking music unworthy of the attention. But Chief Keef has not only sustained creatively in the waning spotlight of his initial breakthrough, he’s become one of the more original young voices in hip-hop. Over the course of the past two years, his music has been in a state of continual reinvention. His latest tape, Back From the Dead 2, is a bold step in a dark new direction. Largely self-produced, it again redefines his sound, pushes his rapping to the foreground, and makes his older records—including the recent Big Gucci Sosa, much of which was recorded more than a year ago—seem quaint.

Though reminiscent of his earlier rap style, Big Gucci Sosa is a mediocre record, and shows the futility of pining for Chief Keef’s supposed golden era of 2012. Admittedly, his biggest records from this time had an immediacy that trumped everything else out there. But Big Gucci Sosa lacks the songwriting of peaks like "Love Sosa", parachuting Keef verses into the one-dimensional pulp-gangster formula that’s been Gucci Mane’s collaborative stock in trade since 2011. Not that Keef is the album’s weak link. On standout "Darker" (which has been in circulation for at least a year), Keef completely washes his mentor.

He stands out again on "Paper", the only song on both Big Gucci Sosa and Back From the Dead 2, if only for a callback to Lil Wayne’s infamous "lasagna" lyric (this one’s about spaghetti). Thankfully, it’s the only pro forma trap record on the latter tape. Sixteen of BFTD2’s 20 tracks are produced by Chief Keef himself. For his first steps into rapper-producer territory, he shows promise—though it’s tough to imagine most of these beats working outside the context of a Chief Keef album, as they are primed to frame his vocals. He’s cultivated a consistent sound; each beat is of-a-piece, with brooding synthesized string and chorale patches moving in beefy quarter notes to conjure a grim yet electric atmosphere. Where the production on 2013's Almighty So had the pace and bleary color of city lights sliding up a rain-drenched windshield, Back From the Dead 2 prowls through back alleys, preferring gritty textures and coiled energy.

In jazz improvisation, there’s a saying that if you screw up, make sure to do it loud—a confident mistake isn’t really a mistake at all. In keeping with this notion, Keef’s production has an amateurism-as-aesthetic element not unlike late ‘90s Swizz Beatz records. The seams show—cymbals take a full beat to decay, waveforms distort, and though he conveys a range of moods, he doesn’t yet have the facility for much rhythmic variation. But Keef’s commitment to the beats’ functional effect blurs the line between "mistake" and mastery—whether through misunderstanding, willful mutation, or both, there’s a savviness and sophistication to the album’s sound. Like many aspects of his musical approach, his conviction makes the unconventional connect.

The main sonic shift from his recent work to this tape is rhythmic. Through loosies released to iTunes and YouTube, Keef’s 2014 output varied from the sudden roller coaster effects of the low-pass filter ("Gucci Gang", "Sosa Style") to the intricate, nimble rhythms of 12hunna’s production ("Hundreds", "Make It Count"). On Back From the Dead 2, tracks like "Whole Crowd" and "Wheres Waldo" seem to float forward, while more groove-driven records like "Farm", "Sets", and “Wayne” are relentless, creeping ahead on four-beats-per-bar tip-toes. It’s not monochromatic; "Faneto" has the feel of a '70s Chinatown sequence, "The Moral" sounds like music from Castlevania, and “Blurry” is all searing exultation. But when compared with this summer’s dynamic, uptempo sound, Keef’s beats are deliberate, the grooves often static—creating a stark contrasting canvas for the dynamism of his delivery.

Keef's rapping holds the project together. His earliest records, like "Everydays Halloween" and "John Madden", hit particularly hard because of a central contradiction: his voice was at once an unbothered flatline and a tool of projection. Keef had Gucci Mane’s nonchalant flow, but his voice popped to the front of the speaker without sacrificing that sense of effortlessness. As he’s evolved, Keef’s detached from that behind-the-beat pocket and shifted to a more aggressive style—one freed from the rhythmic grid other artists treat as a requisite constraint, without being untethered from it altogether, a la certain Lil B releases. This unpredictability lends a chaotic tension to the music.

His lyrics are more effective for their blunt economy—he gets more mileage per syllable (as on the cleverly brutal "Faneto": "Talkin’ out his neck, pistol to his throat/ Blow this motherfucker, he gon’ choke"). He’s unafraid to use space, preferring the compositional effect of short burst phrases, rather than long, familiar cadences. (E–40’s new single "Choices (Yup)" is an example of a more traditional rapper working in this style.) Like King Louie, he will lock into a particular pattern for several lines, using extreme slant rhymes ("I just hit a stain, finagle/ I just hit a stain, finito"), as if trying to demolish the distance between words themselves, or to camouflage his thoughts. He’s made rhyming a word with itself into an art form of its own—he likes to complete the circuit early, or to let words stay static while the meaning shifts ("Nigga don’t slip, you lose it, then you lose it").

Over the course of his career, critics have suggested Keef was a diminished version of every rapper from Waka to Lil B to Soulja Boy. These comparisons now seem absurd; grappling to describe something truly new, we look to the past, and inevitably fall short. Today, Chief Keef is in rarefied air for street rap—a creative voice with an original, cohesive aesthetic. True, in the media spotlight, interest in him is at low ebb: for a certain hipper music listener, he’s not weird enough, eclipsed by the gender-bending, manic Lil Wayne disciple Young Thug. For hip-hop heads, Keef is too weird—and so we end up with a straightlaced (if energetic) street rapper named Bobby Shmurda. Yet to the grassroots, among a new generation of stars, he sits at street rap’s aesthetic center, not its margins.

The subtext of this music remains deeply bleak; there are numerous shouts to his murdered cousin, and it’s extremely disconcerting how casually Chicago rappers refer to kush blunts by the names of fallen enemies. Yet at its heart, there’s a playfulness, both explicit ("I can cut my dreads and sell them on Ebay") and artistic—witness the poetic run-on about money midway through "Wheres Waldo". He plays his own narrative close to the vest, letting his story loom below his elliptical rhymes like ice cubes in a glass. Nonetheless, moments of clarity burst through suddenly, crackling with significance: "And I’m still rollin’ dice, no monopoly/ I can’t be controlled, this ain’t no colony." That line comes from "Wayne", which sounds like a hit rap single turned inside-out to reveal its rotten core—Rae Sremmurd’s evil antithesis. Malevolent and psychedelic, Back From the Dead 2 is Chief Keef’s own "Down 2 Tha Last Roach" blown out to album-length proportions.