A modern rocking chair somehow seems ridiculous. Modernity is all about youth, speed and restless drive -- everything a rocking chair is not. Rocking chairs are synonymous with old, slow, dreamy rumination. Or so it seemed before Ralph Rapson turned out his "rapid rocker," a streamlined machine for the Sputnik era.

In Minnesota, Rapson (1914-2008) is best known as the designer of the original 1963 Guthrie Theater, but his first fame came from the influential furniture he designed in the 1940s for the Michigan firm H.G. Knoll. His airy wood-framed rocker, with its webbed seat and back, quickly became a contemporary classic.

A vintage "rapid rocker" will be the centerpiece of a new Rapson show opening Thursday at Danish Teak Classics, a furniture showroom in northeast Minneapolis. The show will also feature about 25 of the architect's sketches for unbuilt furniture, and a new high-backed version of the rocker recently issued by Rapson-Inc., the family's design firm, now headed by the architect's son Toby Rapson.

In a related venture, Rapson-Inc. and Danish Teak Classics plan to issue a new chair next year based on one of the architect's unrealized designs. Exhibit visitors and online voters can choose one of three designs that will be crafted by local artisans affiliated with DTC:X, a private-label subsidiary of Teak Classics. The winner will be announced Feb. 2 at a closing reception for the show.

The Rapson show and chair project were a natural fit for Danish Teak Classics, which specializes in importing, restoring and selling Scandinavian modern furniture, primarily Danish pieces by such star designers such as Hans Wegner and Finn Juhl. While Rapson is an American designer, his work is "from a period that's a sweet spot with the vintage things we show from the '40s, '50s and '60s," said Teak Classics proprietor Steve Swanson.

"We like the notion of taking a few of Ralph's unrealized ideas and see what they look like in real life, and what interest there is in them," said Swanson, who took architecture classes from Rapson in the 1970s when he chaired the University of Minnesota's Architecture Department.

Winnowing Rapson's ideas to three finalists has been a challenge.

"He did literally hundreds of drawings of not just chairs but tables, flatware, anything," said Toby Rapson. "We've picked some of the more interesting unbuilt chair designs and given them to DTC:X, who are reviewing them to decide which makes sense for their craftsmen."

An endlessly versatile artist, Rapson would doodle chair designs with different leg styles, colors and coverings including fabric, spotted cowhide or woven leather. One popular style had an amoeba-like back, while others had a futuristic look. He loved titles like "chair of tomorrow" or alliterative tongue twisters such as "Rapson rapid rocker."

"They're sort of hokey, but he enjoyed coming up with names for his concepts," said Toby Rapson. "Many are reminiscent of other people's chairs, Eero Saarinen or Charles Eames, but each is different and kind of fantastic. Many of the drawings had people in them, which really separated him from other furniture designers."

Rapson's designs enjoyed renewed interest in the past decade, buoyed by the revival of mid-20th-century modern architecture and furnishings. The year before he died, the 93-year-old Rapson beat out 164 much younger competitors to win a BluDot/Dwell magazine competition to design a new lounge chair. The Minneapolis-based BlueDot firm introduced his winning low-slung metal-mesh lounger at a New York design fair in 2008. Last month another exhibit of his chairs and drawings opened at Archer, a design showroom in Washington, D.C.

Mary Abbe • 612-673-4431