When OK Go embraced formalwear for a concert during the 2004 Republican National Convention, the move was intended to be ironic-a rock band in suits? But, explains lead singer Damian Kulash, "it actually made us less stiff. It added a certain theatricality."

Since then, whether they're mixing glam rock with new wave or dancing on treadmills, as in the hit video that won a YouTube award, OK Go has made a career out of brash, clever combinations. That approach extends to the band's cheerfully mismatched suit jackets and slacks, colorfully clashing shirts, and ties.

Chicago recently invited the fashionable quartet, which formed here in the late 1990s, to assemble four dandified outfits from stores along Milwaukee Avenue. The trip began at Una Mae's Freak Boutique, a Wicker Park fixture that mixes vintage and contemporary wear. Drummer Dan Konopka had mistakenly left most of his dress shirts in New York City a few days earlier, so he picked up a pink shirt with wide stripes by Original Penguin. "It's got sort of a royal vibe," said the drummer, who wore it that night during a sold-out show with Snow Patrol at the Aragon Ballroom. Meanwhile, guitarist Andy Ross chose a vintage brown plaid Pierre Cardin suit; if the band picks up thrift store suits, they have them tailored to a curved, formfitting silhouette, Kulash said.

From left to right: Konopka seeks pink at Una Mae's; Nordwind thrifts at Village; Ross suits up at Hejfina

Walking up Milwaukee Avenue toward the lanky singer's old apartment above the Earwax Cafe, he led the group to Hejfina, where everyone fell in love with the same suit-specifically, a lightweight purple gabardine pinstripe seductress by the utilitarian French line A.P.C. "I'd wear it with lighter colors because the jacket is so dark," Ross said. "Maybe a grayish shirt and a really bright tie."

But this wasn't to be a completely conservative day in OK Go land. A new video for the song "Do What You Want" features the band in suits that match the paisley wallpaper behind them. Bassist Tim Nordwind kept up the trend when he picked out a pair of blue paisley Coast shirts at Scoop NYC.

For accessories, the band hit the sprawling used clothing store Village Discount Outlet. Nordwind rummaged through vests: "These are good to layer with. Sometimes if you've got something crazy on, it'll neutralize it," he said. The others picked out ties and scarves for an added burst of color. The final selection? A quick $1.50 ear of boiled corn from a street vendor. Then it was off to the show.

BUTTONING UP (the OK Go way)

SMOKING JACKET A.P.C. SUIT JACKET , $488, AND PANTS, $210, at Hejfina, 1529 N. Milwaukee Ave.; 773-772-0002 FOLK BUTTON-UP SHIRT, $174, at Hejfina ACNE JEANS VEST, $249, from Hejfina TIE, 60 cents, from Village Discount Outlet, 2032 N. Milwaukee; 773-486-7603 BOW TIE MADE INTO A POCKET SQUARE, 20 cents, at Village

PLAID PANTHER PIERRE CARDIN PLAID SUIT JACKET, $36, AND PANTS, $24, from Una Mae's, 1422 N. Milwaukee; 773-276-7002 ORIGINAL PENGUIN BY MUNSINGWEAR BUTTON-UP SHIRT, $58 marked down to $40, at Una Mae's BOW TIE TURNED INTO A POCKET SQUARE, 40 cents, from Village

Photography: Selena Salfen