For years, a cheerful blue-and-yellow mouse sculpture by the artist peered down on the garden from the rooftop terraces of nearby Walker Art Center, and visitors to the museum often would encounter Oldenburg’s eccentric soft sculptures — a 9-foot-tall bag of shoestring potatoes tumbling onto the floor, or a gigantic electrical plug dangling over a stairwell.

Given the bold scale and whimsical charm of such art, it’s natural to think of Oldenburg, 84, as just a clever jokester having fun with Pop culture. That’s not wrong, but there’s a whole lot more to the guy as seen in “Claes Oldenburg: The Sixties,” a deep-dish survey of his work from a protean decade that was way messier, more rambunctious and improvised than his polished later art suggests.

Organized by Vienna’s contemporary art museum, the 300-piece show opens at the Walker on Sunday and will be on view through Jan. 12. Minneapolis is the last stop on a tour that debuted in Vienna and included venues in Cologne, Germany and Bilbao, Spain, as well as the Museum of Modern Art in New York.

The ’60s represented a legendary era in American art, an explosive decade when Roy Lichtenstein turned comic book scenes into million-dollar paintings, Robert Indiana made LOVE into a logo and Andy Warhol fashioned soup cans into art.

Somber-minded Abstract Expressionism was on the wane by 1960, its loopy gestures, lyrical effusions and high-minded theory increasingly out of touch with the gritty reality of life in Manhattan, then the world’s art capital. Plus there were new kids in town, eager to knock the establishment off its pious pedestal and launch something different.

Oldenburg was among the fresh faces. Born in Sweden, he grew up mostly in Chicago, where his father was a diplomat. After studying at Yale and the Art Institute of Chicago, he settled in New York in 1956 and has lived and worked there ever since.

Street, Store and Home

The Walker’s three-gallery show opens with crude drawings and rough cardboard cutouts from “The Street,” a 1960 installation of graffitilike figures and bruised body parts whose edgy chaos conveyed a sense of urban decay. Snapshots from the artist’s notebooks of the time footnote Manhattan’s shabby industrial underbelly.

Around the corner are relics from his famous “The Store,” a 1961 installation-shop in his storefront studio where for several months he sold sloppy, paint-splashed wire-and-plaster sculptures shaped like shirts, ties, cigarette packs, baked potatoes, cheeseburgers, pastries, lingerie and other commodities. A simultaneous critique and celebration of American consumerism, “The Store” was a guerrilla-theater performance in which the slapdash sculptures also poked fun at the grand gestures of Abstract Expressionist paintings.

He began making “The Home” objects, displayed in the next gallery, around 1963 and continued through the decade. Here’s where his genius really soars, as he transforms ordinary objects — light switches, toilets, a bathtub, a fan and a vacuum cleaner, electrical plugs — by enlarging them to monstrous proportions and fashioning them from hard or incongruously soft materials such as canvas or vinyl that deliberately provoke fanciful, often sexual associations.

In a series of drawings and sculptures, a soft vinyl electrical plug suggests a cow’s gigantic udder, while a half-buried hard plug morphs into a house. Likewise, a 5-foot-square double light switch, made of canvas, droops and sags like an old woman’s breast, its light switches protruding from their sockets like distended nipples.

“His forms are transmuted and tend to have a human reference,” said former Walker director Martin Friedman, who bought or commissioned many of the museum’s Oldenburg works. “The hard forms have a skeletal association and the soft ones are like skin and flesh; that’s very important.”

Imaginative transformations

Throughout the show, the artist applies his protean imagination and remarkable drawing skill to surreal effect, transforming women’s legs into shoestring potatoes, lipsticks or cigarettes; proposing a gigantic-drill-bit fountain for a London square; turning stylized mice heads into film projectors, a cannon, an electrical plug and even ray guns — a sci-fi toy whose mutability became a metaphor and curious alter ego for the artist.

Because “The Sixties” focuses primarily on a single decade early in Oldenburg’s career, it unfortunately doesn’t trace his formidable influence on contemporary art, with its obvious echoes in the dysfunctional plumbing fixtures of Robert Gober and the scale shifts of Jeff Koons, to cite just two examples. He introduced humor and play into the previously somber field of sculpture, was a proto-feminist who sewed fabric sculptures, and pioneered happenings and multimedia performances.

“His early art still seems very fresh today,” said Walker curator Siri Engberg. “He did all of it ­­— installation, performance, drawing, painting, sculpture — they all had equal weight to him. From the start, he was just an artist.”