If you need cheering up, go to the Museum of Modern Art and look at a painting called “Oof,” by Edward Ruscha. The title and the subject are identical, just those three block letters, each one bigger than your head, in cadmium yellow on a background of cobalt blue. The six-foot-square canvas currently hangs in Gallery 19, on the fourth floor, along with Roy Lichtenstein’s “Girl with Ball,” Andy Warhol’s “Gold Marilyn Monroe” and “Orange Car Crash Fourteen Times,” and other Pop Art trailblazers of the early nineteen-sixties. “Oof” outdoes them all in its immediate, antic impact. This is not the kind of picture that reveals hidden depths on subsequent viewings. Everything is right there, every time, and it never fails to make me feel good.

Ruscha (pronounced Ru-SHAY) was twenty-six when he painted it, in 1963, three years out of art school, living in Los Angeles, and already hitting his stride. He had vetoed the spontaneous, loose-elbow, Abstract Expressionist style that still prevailed at the Chouinard Art Institute, where he studied in the late nineteen-fifties, shortly before it became the California Institute of the Arts (CalArts). “They would say, Face the canvas and let it happen, follow your own gestures, let the painting create itself,” he later recalled in an interview, but that didn’t pan out for him. Ruscha had seen, reproduced in the magazine Print, a Jasper Johns collage painting called “Target with Four Faces,” and it had opened up a new range of possibilities. He decided that whatever he was going to do in art would have to be “completely premeditated.”

He made a few Johns-influenced paintings. One showed a can of Spam rocketing through space; in another, a real box of Sun-Maid raisins was flattened on a canvas, above the partly painted-over place name “Vicksburg.” Very soon, he zeroed in on the Johnsian notion of painting words. “It was so simple, and something I could commit to,” he said last winter, when I visited him in Los Angeles. Ruscha, at seventy-five, is lean and fit, and his natural reserve is offset by an easygoing friendliness. We were sitting in the library and office space of his immense, warehouse-like studio in Culver City, which he moved into two years ago. Los Angeles was having a cold snap, the heat wasn’t working, and Ruscha had lent me a heavy-duty parka to wear. “I would settle on a word like ‘boss,’ ” he said. “That was a powerful word to me, and it meant various things—an employer, and a term for something cool. Also, a brand of work clothes.” “Boss” appeared in 1961, black letters on a dark-brown background, and was followed, during the next three years, by “Honk,” “Smash,” “Noise,” “Oof,” “Won’t,” and other word paintings. He chose commonplace, one-syllable words that had what he described as “a certain comedic value.” “Oof” was different—onomatopoeic, for one thing, and funnier. “It had one foot in the world of cartooning,” he explained, speaking slowly and lingering over a word now and then, as though to savor its quiddity. “You get punched in the stomach, and that’s ‘Oof.’ It was so obvious, and so much a part of my growing up in the U.S.A. I felt like it was almost a patriotic word.” Ruscha, who was born in Omaha in 1937, and spent his childhood in Oklahoma City, may be the only living American who can discern patriotism in a grunt. Our conversation was interrupted at this point by Woody, a large, thirteen-year-old mixed-breed and somewhat arthritic dog, who was making plaintive noises; Ruscha got up and helped him out the back door.

“Oof” had an adventurous early life. Ruscha lent it to his childhood friend Mason Williams, and a few years later, when Williams was working as the head comedy writer for the Smothers Brothers, he let Tommy Smothers borrow it. The picture fell off a wall in Smothers’s house and landed face down on a chessboard, whose sharp-tipped metal pieces punctured the canvas in several places. Ruscha took it back, got it repaired, did some repainting, and kept it until 1988, when a group of very wealthy donors bought it for the Museum of Modern Art.

Language has often invaded the visual arts during the past century, but no other artist uses it the way Ruscha does. His early paintings are not pictures of words but words treated as visual constructs. “I like the idea of a word becoming a picture, almost leaving its body, then coming back and becoming a word again,” he once said. “I see myself working with two things that don’t even ask to understand each other.”

Los Angeles was largely oblivious of the visual arts in the early nineteen-sixties. Unlike San Francisco, which considered itself the cultural capital of the West, L.A. had no significant art museum, few galleries, and only a handful of people who would even think of buying contemporary art. It did have a crop of obstreperous young artists, though, and in 1962 Walter Hopps, a former U.C.L.A. student who had just been named curator of the quaint, unassuming Pasadena Art Museum, put several of them in a group exhibition there called “New Painting of Common Objects.” It was the first American museum show of what would soon be known as Pop Art, and it included, along with works by Roy Lichtenstein, Andy Warhol, and Jim Dine, three recent paintings by Ed Ruscha.

A year later, Ruscha had his first one-man show at the Ferus Gallery, which Hopps and the artist Edward Keinholz had started in 1957, in the back room of an antique shop on North La Cienega Boulevard. In addition to his single-word images, the 1963 Ferus show included the more ambitious “Large Trademark with Eight Spotlights,” an eleven-foot-wide view of the Twentieth Century Fox logo as a three-dimensional monolith, and “Noise, Pencil, Broken Pencil, Cheap Western,” in which the word and the three objects, meticulously reproduced in their actual sizes, seemed to be trying to escape from the picture. The paintings were priced between a hundred and fifty and four hundred dollars, and six of them were sold—a remarkable début. That same year, Ruscha finished “Standard Station, Amarillo, Texas,” the first of his many paintings, drawings, and prints of gas stations, whose dramatic, raked perspective came from an effect he had observed in old black-and-white films. “You know those movies where a train starts out in the lower-right corner and gradually fills the screen?” he asked. “The gas station is on a diagonal like that, from lower right to upper left. It also had something to do with teachings I picked up in art school, about dividing the picture plane. I didn’t really know what I was up to then, or what direction to take. I was just following these little urges. It was pure joy, to be able to do something like that.”

In 1965, the opening of the Los Angeles County Museum of Art in its Wilshire Boulevard location signalled a new era in the city’s cultural development. Ruscha observed the event with another eleven-foot-wide painting that showed the museum complex in all its boxy, corporate-modern banality, but with smoke and flames shooting out of the Ahmanson Building, and not a single human being in sight. “Los Angeles County Museum of Art on Fire” and several other Ruscha paintings of burning buildings are sometimes cited as evidence of a “dark side” in his art, but they don’t seem dark to me. My guess is that he really liked painting orange flames. The LACMA picture does give rise to thoughts about the city’s expanding cultural pretensions, though, and I asked Ruscha whether this had been part of his intention. Not really, he said. “I went on a helicopter ride over L.A., and took some Polaroid pictures of the museum from the air, and it just sort of went on from there.” But the fire? “Well, there’s always a little room for questioning authorities.” Joseph Hirshhorn, the uranium millionaire, bought the painting in 1968, and eventually gave it to the Hirshhorn Museum, in Washington, D.C. This is a source of undying regret to Michael Govan, the current director of the Los Angeles County Museum, who considers it a quintessential Los Angeles picture.