Put on Blocboy JB’s new mixtape and behold a testament to the virtue of precision in hip-hop. Simi, out since May, overflows with party-friendly beats, palatable hooks, amusing verses and incisive apercus, but its fundamental pleasure lies in a coldness that’s rare in rap and any kind of upbeat pop music. This music celebrates the pedantic thrill of aligning the drum track with the keyboard line, the sharpness that arises only when everything is in its right place. It’s the most meticulous demonstration of formal rigor hip-hop fans will likely hear all year.

Blocboy JB arose in the Memphis mixtape scene, where he established himself as a prolific creative presence, dropping six tapes in little over a year between June 2016 and September 2017. A tenacious but also comical street rapper, he scored enough hits and filmed enough viral dance videos to achieve a certain degree of infamy, eventually collaborating with Drake on the top 10 single “Look Alive” earlier this year and becoming known as a Drake protege.

I hope Drake, who views rookie rappers like large tech companies view startups, doesn’t absorb him altogether — careerwise, the acts on Drake’s OVO Sound vanity label have all shot themselves in the foot by attaching themselves to a powerful man. But Blocboy doesn’t suit the anhedonic Drake aesthetic, which tends to favor softer, singier performers better suited to drowning in pools of lightly bleached synthesizer fog.

Blocboy, by contrast, raps with infectious exuberance and percussive force, a deep-voiced, obstinately masculine twister of syllables and progenitor of surreal inflections. As a rapper, he distinctly recalls 2 Chainz in his defiantly bemused tone and theatric bewilderment at the existence of people who don’t consider him the greatest rapper alive, but he’s more rhythmically inventive, enlivening his mechanical triplets with stutters, whoops, speedy juxtapositions of multiple flow patterns into a single verse. That Blocboy’s breakthrough hit “Shoot” initially became famous for his dance in the accompanying video is apt, for he’s a performer dedicated to the exhilaration of physical motion.

Simi moves with magisterial expertise. He’s crafted his seventh mixtape like an album, calculated for maximum sonic consistency and fluidity. Blocboy’s stage name notwithstanding, the spare, sweeping, piano-driven sound pioneered by producer Tay Keith and associates is too flowing to qualify as blocky, an adjective that in hip-hop implies a sort of cartoon pixelation; Glideboy or Soarboy JB would be a truer approximation of what the record sounds like. Minimalist piano chords march in tandem with skittering snare drums, rushing by with shrewd elegance.

The queasy “Nun of Dat” gradually uncoils over two alternating piano lines, one an ordinary high, mid-tempo trap hook, the other a lower arpeggio played quickly enough to crumple into a wobbly hypnotic blur. The first hook dominates the verses, leading the song’s simple forward motion, before the other one takes over and destabilizes the music, turning the song into a valiant attempt to control a creeping nausea; it spirals around and around as your head spins. Blocboy’s deep, vibrant shouts add contrast and gravitas, a musical anchor in a swirling sea.

“Shoot,” his breakthrough, typifies his sensibility: the snap of the drums, the billowing synthesizer and echoey ad-libs (“Ya! Ya ya ya ya!”) produce an upbeat but ambient backdrop for Blocboy to utter a set of verses that get progressively speedier, showing off his rhythmic command. The one-word chorus (“Shoot! Shoot! Shoot! Shoot!”), delivered in a high, percussive monotone, is a sharp musical slash disguised as a bliss point.

Meanwhile, the more conventional piano loops in “Wait” and “Rover 2.0” spin with martial regularity, providing consistent musical baselines Blocboy’s playful rhythms and subtle electronic vocal flourishes, foregrounding his enunciated raps while turning the ad-libs into a murky vocal hall of mirrors. These songs are enacted triumphs of clarity.

Coded as street rap, which means trap, Simi represents the gradual shift of trap conventions toward supposedly more classicist virtues: spareness, unflappability, exactitude. The hooky beats and Blocboy’s rapping suggest functionalism — formalist product designed to excel within previously established pop styles — and Simi is indeed an upbeat party tape, a marvelous soundtrack for social festivities. Nonetheless, recent developments in party rap have favored modes of musical immersion antithetical to vocal and lyrical intelligibility — Playboi Carti’s gorgeously blurry, wholly incomprehensible albums apotheosize this tendency — and Simi offers a corrective.

Stylistically, Migos are a clear precedent, as definitively trap-identified rappers who combine trap’s irresistibly playful goofiness and devotion to the ad-lib with rapid, lucid, patently skillful verses designed as displays of virtuosic technique, especially on their flawless touchstone Culture (2017). Migos’s reigning mood, the amused jollity characteristic of so much recent trap, ensures a lighthearted buoyancy that marks their songs, conclusively, as pop product. Blocboy takes things a step further: he’s not cheerful at all. The hooks on Simi, delightful as they are, aren’t centralized e as they would be on a pop-rap album; they’re one element in a larger kinetic musical space. A rap mixtape whose dominant pleasures lie in the athletic mastery of motion, impeccably streamlined efficiency, and neat formal lines, is a rap mixtape that cultivates a forbidding, determined, composed tone. Likewise, Blocboy’s rhythmically unpredictable, plainly enunciated rapping displays a dexterity that fits the music exactly.

Theoretically, this is what old-fashioned rap fans want from the genre: technical proficiency, standards of clarity, the fetishization of control. Playboi Carti, say, represents a threat to conventional values in hip-hop because his hazy musical overload suggests takeover of the id; a rapper who mumbles is terrifying because he may not be in control of his music. Blocboy’s bellowed chatter is almost conservative by comparison: the comforting return of the steely authorial hand.

Soaring through space like an aerodynamic electric train, a streamlined surge of energy, Simi captivates in its methodical formalist rigidity. Excited but also imperturbable, Blocboy raps on behalf of all those who decline open hedonism for the perversity of finding joy in coldness and abstraction. Asceticism is its own delight.

Lucas Fagen's favorite artform is popular music, and that means popular music—bland corporate trash and faceless functional product in addition to critically respectable touchstones and obscure dregs...