In December 2016, Ka posted a photo of a newspaper clipping to his Twitter account. It was a short item about the Cuban American artist Carmen Herrera, who, at the age of 101, had recently received her first solo exhibition at a major museum. In the 1940s and ’50s, she had begun to restrain herself, clarifying a minimal but dynamic approach to abstract expressionism—but, the paper lamented, was ignored by an art world too fixated on her “macho” contemporaries. Over nearly 70 years, working on a tier just above obscurity, Herrera seemed to strip from her work any element she deemed extraneous. “Patience, dear, patience,” she’s quoted as saying the day before her Whitney opening. The headline reads “VINDICATED.”

At the time, Ka was 44 years old, five albums into a career pivot that turned an also-ran from the crowded New York rap scene of the 1990s into one of the genre’s great auteurs. “For those that feel they don’t get the recognition they deserve,” he wrote, “this may change your perspective.” Over the last decade and a half of his life, Ka, who passed away over the weekend at the age of 52, worked much like Herrera, refining his quiet yet forceful style until only what was truly essential remained. The final ten albums he released, from 2012’s scythelike Grief Pedigree through this summer’s The Thief Next to Jesus, represent one of the richest, most stylistically inventive catalogs in the history of hip-hop. Taken as a whole—or broken down into one of the simple couplets that are its component parts—they articulate a belief that falling short of your personal ethics is the purest form of cowardice.

Born Kaseem Ryan and raised in Brownsville—a neighborhood that he always called home and would figure largely into his work—Ka first carved a niche as a member of the group Natural Elements, and then one-half of the duo Nightbreed. But by the turn of the century, he had abandoned the pursuit of a music career and taken a job in New York City’s fire department, where he eventually became a captain and served as a first responder to the September 11 attacks. (The latter fact was pointed out in a pathetically sober obituary in the Post, which years earlier had smeared him for his “anti-cop lyrics.”)

By the mid-2000s, encouraged by his wife Mimi Valdés—the former editor of Vibe—Ka had begun writing and recording again, though this time simply for personal fulfillment. In 2008, he self-released an album called Iron Works, an embryonic version of what would be fully realized on Grief Pedigree. That same year, GZA tapped him to appear on his album Pro Tools. “Firehouse” is effectively a solo platform for Ka, with the headliner appearing only on the chorus. It’s an incredibly arresting performance. Ka sounds as if his vocal cords are being sawed through; his boast, in the opening ad-libs, that he’s representing “every block I ever lived on” is exhilarating for the way it simultaneously narrows the scope of his writing and heightens the stakes of its most seemingly minor conflicts.

The individual elements of Ka’s style would be familiar to a listener with even a cursory knowledge of rap. He wrote about power struggles in his neighborhood and about the sharpness of his own pen; he was fond of tidily straightforward wordplay, like saying that he was “at the bottom/That’s where all the tops is slung.” But these pieces were arranged in a way that made the familiar seem foreign; through his razorlike rasp, he could make a rote observation sound like conspiracy, harrowing details and sweeping indictments of character seldom rising above a whisper. Ka’s music, which is largely self-produced, is at once stark and enveloping, a fugue of dread and predatory housing law punctured by shards and wisdom and, occasionally, discrete moments of joy.

Over the course of the 2010s, Ka’s stature in rap’s underground grew steadily, from curiosity to cult hero to wizened elder. I’ll speak anecdotally here: I cannot think of another living rapper who was spoken about so reverently by his contemporaries. The admiration was universal and it was absolute. The fact that he continued to ship records himself (and even deliver some local packages by hand) was often cited as a sort of moral good. Maybe it was. But it always scanned to me less like performed humility and more like the inevitable extension of his worldview. His music was handmade, labored over, and ultimately physical in nature: as pared down as his syntax and instrumental arrangements often were, the songs gained their own internal rhythms, his meter implying momentum at the same pace as the story beats in the parables he loved. He was going to be above packing an envelope?

I return to Ka’s music seasonally. As soon as it feels cold in my neighborhood, I run through his catalog—sometimes sequentially, sometimes at random—and find myself lost in those crevices of Brownsville, of greater 1980s New York, of Ka’s psyche as he strove to live up to the maxims he first heard on the city’s stoops and in its subway cars. My favorite song of his is one of his most pointed: “$,” from Honor Killed the Samurai, which was released the same summer Carmen Herrera had her exhibition at the Whitney. “You telling stories that’s celebratory in times of war,” he raps. “With bars of greed, I plead: How many cars you need?/When fathers bleed to fill ribs of kids that hardly read.” These lines are delivered with venom, but the overwhelming feeling is not contempt—it’s disbelief. It was unthinkable to Ka that each moment of one’s life would not be in service of a whole, or that that whole would not be in service of one’s family and community. And the songs followed this logic, molting bit by bit, year over year, the changes barely perceptible in the moment, until a full evolution had occurred. He worked, monastically, toward an ideal, discarding from his art piece by piece until only the truth remained.