In the first issue of his graffiti and pop-culture magazine While You Were Sleeping, Roger Gastman thanked “Mom for the loot,” and then thanked “everyone who ever told me that graff was a dumb waste of my time.” Gastman, who was 19 at the time, had already been running a graffiti supply business in Bethesda, Md., for three years and was starting to assemble a valuable collection of graffiti ephemera, sourcing discontinued Krylon paint colors at mom-and-pop hardware stores as though he knew, even as a teen, that his obsession would serve him well.

Now 33 and living in Los Angeles, Gastman is still having the last laugh. The Museum of Contemporary Art, Los Angeles, is gearing up for the April opening of “Art in the Streets,” a major graffiti and street-art survey he’s curating along with the museum’s new director, Jeffrey Deitch, and the independent curator Aaron Rose. “The History of American Graffiti” (HarperCollins), written by Gastman and Caleb Neelon, also comes out next month.

While the tattooed, baseball-capped Gastman says he wasn’t expecting the e-mail he received from Deitch about the MoCA show, “I sort of feel like I’ve been training for it my whole life.”

He was introduced to his calling in the streets of Washington, D.C. “Everyone had a tag,” he recalls, sitting under an Adam Wallacavage octopus chandelier in his Los Feliz living room. “It was just what you did.” His skills may have been “average at best,” but he was there — climbing the rooftops, painting the freight train cars and documenting it all. He says his tight network of artists, collaborators and friends is simply a product of being in the right place at the right time — he met the now legendary Saber under a bridge when he was 15 — and an ability to keep his word. “Most people are flaky,” he says with a shrug.

WYWS Magazine Covers

“What I really liked about Roger from the beginning,” says Shepard Fairey, a fixture in the pages of While You Were Sleeping and later Gastman’s partner in Swindle magazine, “was that he seemed really self-motivated, smart, funny and irreverent. But he’s also professional enough to put out a magazine and organize all the moving parts that go into that. It’s a pretty unique blend.”

Swindle — named in honor of the Sex Pistols movie — came out from 2004 to 2008, years that saw seismic shifts in the impact and visibility of street art and graffiti. Banksy’s 2006 “Barely Legal” show in L.A. was heralded on one cover, featuring his spoof of a naked, pregnant Demi Moore. In early 2008, Fairey designed the Obama “Hope” graphic. By the time Gastman was called in to help Mr. Brainwash, a k a Thierry Guetta, an eccentric Frenchman obsessed with street art, mount a massive show on Sunset Boulevard, Fairey and Banksy were practically household names.

To everyone’s surprise, the Banksy documentary “Exit Through the Gift Shop,” which explores the street-art phenomenon through the story of Guetta’s unlikely ascent, received lots of mainstream attention. (Gastman was a consulting producer on the film and also has a cameo.) “I keep thinking the bubble’s gonna burst, this can’t get bigger,” he says. “Then somebody pushes something else.”

According to Deitch, graffiti/street art is the most influential art movement since Pop, and the level of interest from the public and from scholars is what necessitated the show. “It’s so big,” he says. “The museum world now has to acknowledge it and look at it from a historical point of view.”

Some may think the two are interchangeable, but Gastman says street art and graffiti are “very different animals.” The former is iconic and message-driven, while graffiti is simply the practice of writing your name over and over again for the sake of fame: “They want to be king of their block.”

Aware of the inherent irony of a curated museum show celebrating mostly illegal, temporary outdoor art, Deitch and Gastman have chosen to focus on those artists who have gone on to build serious careers. A large part of the exhibition will be installations by mythic outlaws like the subway painter and “Wild Style” star Lee Quiñones and Chaz Bojórquez, whose style draws from cholo gang graffiti and Asian calligraphy. There will also be works by still-rising stars like Miss Van and Revok. Fun Gallery, the East Village storefront where Patti Astor showcased graffiti and gave early shows to Jean-Michel Basquiat and Keith Haring, will be recreated on-site.

Fairey, who will also be doing an installation, says Gastman’s presence is a buffer. “With a crowd of people so inherently suspicious of the wielders of power — the gatekeepers — to have somebody like Roger involved is extremely important.” Still, Gastman, who has curated art shows for clients like Scion and Sanrio, knows that a stamp of approval from the establishment only carries so much weight for artists who have chosen the street as their gallery. “They’re excited to be in a museum setting,” he says, “but they’re also still really excited to go paint a huge wall off the freeway.”

By Steffie Nelson for NYTIMES Photography: Jessica Haye and Clark Hsiao