The North Carolina producer L'Orange has spent the last few years slowly building a signature sound, rooted in the past yet wholly his own. You can trace a line between his MPC rips of vinyl back to Madlib's zonked-out tapestries on Madvillainy, and Daedelus' surrealist lounge music for The Weather. But over the past few years, and especially in 2015 through projects like The Night Took Us In Like Family (the latter made with L.A. rapper Jeremiah Jae), the man who bears the same name as Gilbert Bécaud's 1964 French chanson has cobbled something unique. On his best work, he stacks his snatches of vocals into something approaching a narrative, adding bebop and exotica tones and keeping rhythmic tension from slumping.

His second project this year finds him collaborating with Kool Keith on Time? Astonishing! Structurally, it's an adventure, heavy on vague metaphysics and B-movie ramblings about space travel. One of its charms is hearing L'Orange adapt his sound to fit the mercurial Kool Keith's style. He abandons the ornamental quirkiness of The Night in favor of yearning melodies, like the melancholy guitar loop of "Twenty Fifty Three", or the choral harmony and dusty jazz piano od "Meanwhile Back Home". The vocal samples are still there, though. On "This New World", he layers "underwater" effects onto a snippet of Flavor Flav asking, "What goes on?" and makes it resemble an outtake from Parliament's "Aqua Boogie".

As for Mr. Keith, listeners will note parallels to his vaunted Dr. Octagonecologyst, especially when it comes to the bludgeoning, Automator-inspired bass thump of "Dr. Bipolar". However, Time might hew closer to Keith's criminally underrated 2006 collaboration with Tom C, Project Polaroid, which also found him speaking in a halting delivery, underlining the weight of his words. Here, it seems as if he's floating through the music, then going silent as it swirls around him. His restrained performance pays the most dividends on "The Wanderer", where he bends together incongruent images in his familiar Bronx drawl: "The structure of combat is like Wrestlemania contracts/ Genetics make the eye contact/ Shaggy mister boom back denim/ I have nothing to prove in slacks." Then there's his bizarre battle rap on "I Need Out of This World": "Come again if you're a male with a fitted wearing a toupee/ I can get you an inside job wearing daishikis."

Keith's deliberate opacity and "upper-class penmanship" is trailed by a panoply of guests. On "The Traveler", he drops a tantalizing verse—"See the cerebrum, how fast I'm passin'"—and then cedes the spotlight to J-Live, who "disappear like I never here." Mr. Lif hijacks "Twenty Fifty Three" with Boston-accented super-scientifical madness. Open Mike Eagle tackles "Meanwhile, Back Home" alone, with Keith nowhere to be heard. Blu, MC Paul Barman (of all people), and MindsOne—individually, they range from serviceable to splendid. But cumulatively, they distract from the chemistry between the album's two main performers. Then again, perhaps Kool Keith and L'Orange are satisfied with conjuring a mood of amusingly hallucinatory hip-hop that lasts just over 30 minutes, and then evaporates like a pleasurable high. Whether it will be remembered as Time passes remains to be seen.