Martin Wong, Medici of the Aerosol Art Set

Martin Wong got in with the graffiti writers in the early 1980s at Pearl Paint, the long-gone Canal Street art supply store, where he had a job in the canvas department. Wong would slip them markers or cans of spray paint or sell them supplies on deep, unsanctioned discounts, which endeared him to artists at crucial moments of their careers. The painter Lee Quiñones recalls Wong writing out $20 invoices for portrait-quality linens priced at $400.

Wong soon began buying Quiñones’s work and that of like-minded painters like Daze, Sharp and A-One — artists who were moving away from bombing trains with graffiti and developing studio practices. In so doing, he nurtured their development and became a constructive patron: a Cosimo de’ Medici of the aerosol set. His collection is highlighted in “Above Ground,” a small but essential exhibition at the Museum of the City of New York.

By 1994 Wong had amassed upward of 300 artworks and other media, all of which he donated to the museum that year. As interest in both the modern graffiti movement and its diasporic reverberations has grown, Wong’s conviction has proved consequential, his collection functioning as a repository. Pieces from it have been lent to major institutional surveys, like “Writing the Future: Basquiat and the Hip-Hop Generation” at the MFA Boston and “Art in the Streets” at the Museum of Contemporary Art in Los Angeles, shows that have deepened scholarship of this previously maligned and misunderstood period.

Outsiders had been hot on graffiti at the same time as Wong was, but none had a more ardent or abiding interest. He recognized what was an irreducible form of American expressionism and its importance in the history of New York, even as much of the city was hostile toward it.

Wong was 32 when he arrived in New York from San Francisco in 1978 and was drawn immediately to the baroque layers of tags spreading across the city’s surfaces. Wong’s own art, an urban realism that synthesized documentarian detail and romantic devotion (no artist lavished more attention on bricks), had little technical overlap but shared a sympathetic kinship. His paintings referred to the street, and so invariably referred to graffiti too. He reproduced the Lower East Side’s tagged handball courts and crumbling redbrick tenement buildings as oppressive but softened, bathed in a dingy cast that can feel like ecstatic reverie.

Wong appears to have never attempted a tag, though there were other affinities. He had a degree in ceramics but was a largely self-taught painter, and he most likely appreciated the graffiti writers’ similar industriousness. There was an overlapping interest in language; despite being neither deaf nor mute, Wong learned and practiced American Sign Language. His tidily compressed hand signs punctuate the realism of his scenes, not unlike the alternative writing system of graffiti’s letter forms.

But perhaps most of all, Wong was sensitive to otherness and underclass. A gay Chinese American, Wong surely recognized in graffiti — an art invented by kids in the city’s marginalized communities and forgotten-about peripheries — a version of himself.

The breadth of Wong’s collection invites many interpretations. “Above Ground,” curated by Sean Corcoran, is the second exhibition the Museum of the City of New York has carved out of it. “City as Canvas,” from 2014, was the first and, as testament to the abundance of Wong’s collection, the new exhibition includes scarcely any overlap. Whereas “City as Canvas” aimed to provide a primer on the emergence of graffiti and justify its artfulness, this new iteration takes those ideas as a matter of course.

“Above Ground” opens with a compressed refresher on the 1970s organizing efforts of crews like United Graffiti Artists, who painted live during Twyla Tharp’s Joffrey Ballet performance, and Esses Studio, which gave many subway writers their first exposure to canvas. The exhibition then becomes a deeply tuned analysis of the advances of the 1980s (the crucial period of graffiti’s embrace by the gallery system), the form’s shift from raw expression into commodity, and the stylistic ruptures that flowered.

It includes work from familiar names like Futura and Haze (who is also responsible for the exhibition’s graphic design and the frieze ringing the gallery’s clerestory windows), but also, happily, lesser-known artists like A-One, Delta-2, Ero and Kool Kor. There are several indispensable examples of work by Rammellzee, who created a philosophically dense Gothic Futurism completely his own.

Some of the standouts have never been on view before, including Quiñones’s “Breakfast at Baychester” (circa 1980), a startling, near-schematic of a pair of No. 5 trains parked in the Bronx layup that was a favorite painting ground among writers. The piece was unfinished when Wong acquired it, which may account for its haunting beauty, its mechanical guts still being sketched in, both spare and intensely detailed at once. A smaller ink-on-paper study finished three years earlier hints at the vision, an energetically cartoony homage to other writers’ tags, but there’s a sober realism to the incomplete work.

Wong was a completist, interested in not just the juicy, fully realized canvas works but also rarities and the stuttering starts. The show includes “Kaygee” (circa 1985) a small aerosol on canvas by Dez, a writer who created florid murals and appears to have never produced another canvas. There is also a mesmerizing tromp l’oeil, “Green Krinkle in Stereo” (1983) by Stan 153, a prolific but underappreciated stylist who was early to understand graffiti’s commercial applications.

Throughout the show, you get the feeling of Wong’s intention, his vision of a comprehensive history of graffiti in New York. There are pieces dated as early as 1971, scraps of cardboard busy with tags, writers’ earliest scribbles and school notebooks, when they were still working out their tags and hand styles. “Martin collected childhoods,” the artist Daze noted.

Wong’s support eventually evolved into advocacy. With Peter Broda, he opened the Museum of American Graffiti on the top floor of a townhouse on Bond Street in NoHo in 1989, by which time graffiti had mostly dried up in the subway system and the galleries’ fast-burning affection had cooled. (The Village Voice ran the headline “Graffiti R.I.P.” in 1987.) It closed within six months, but the inclusion here of one of the original display vitrines, its wooden frame spangled with thick, loping marks, is a subtle fulfillment of Wong’s vision; you can make out the fresh tags squeezed in between the ones from 35 years ago. It’s an affectingly living work.

Diagnosed with H.I.V., Wong returned to California in 1994, where he died five years later. He could have easily sold off pieces to European collectors to fund the last years of his life, but he was adamant that his collection remain intact and in a public institution, a double gift. Like all major art collections, Wong’s represents a bet, less in graffiti’s appreciable sales value than in its ability to make visible what was before an invisible segment of society. Wong’s bet is paying off, even as institutions that bought his own work remain indifferent to graffiti. That they still haven’t caught up tells you how far ahead he could see.

Above Ground: Art From the Martin Wong Graffiti Collection

Through Aug. 10, Museum of the City of New York, 1220 Fifth Avenue, Manhattan; 917-492-3333, mcny.org.