WHAT HAPPENS to styles that go "out"? Ususally they come back 50 years or so later, somewhat reworked and refined to capture the fancy of succeeding generations.

One recent example is the "Normandie Moderne" group by Milo Baughman with its soft flowing curves based frankly on the "Moderne" look of the late 1930s and epitomized by the "streamlined" Normandie ocean liner.

For many years Baughman, the designer for Thayer Coggin furniture, has watched the comings and goings of "What's out and what's in" evolve in a cycical pattern. He believes that 1930's Moderne style has returned to inspire not only furniture, but other design areas.

The Normandie liner appeared when the United States was recovering from its most severe depression. People responded eagerly to its luxurious grandeur.

"There may be a real psychological need for the same kind of compensating glamor. Though our economic problems are not as serious as those of the '30s, we may once again be hungering for the same feeling of super-smooth sophistication. We haven't developed an identifiable post-modernism in furniture to go with the new post-modern architecture as yet, but . . . it seems to me that the design spirit of the late '30s fits particularly well our need in the '80s for tactile, visual and emotional comfort -- and, above all else, that indefinable something called glamor," Baughman said.

Sleek and sophisticated, but also practical and relevant to the present, Normandie Moderne, as interpreted by Baughman, does seem appropriate for the 1980s without showing its age. Baughman gave consideration to smaller living spaces in condominiums, town houses and city apartments, though his designs are far from diminutive. Curvilinear sofas and chairs don't have to be backed against walls. They can be angled freely in any space to achieve a less rigid, more spacious effect with a room.

An elliptical dining table with laminated color base and glass top brings to mind the graceful contours of an ocean liner. Complementary curves are reflected in upholstered dining chairs. For sofas and lounge chairs those curves are broadened and deepened.

Adapting the ellipsis to other subjects, Baughman has done a cocktail table with a swivel top that, when fully opened, almost doubles its surface. An oval console table on an oval base accommodates a pair of upholstered ottomans shaped to fit snugly beneath the wings of the table. It's an adaption of an idea that has been around for some time, but the new one has a sleekness that is refreshing and as classic as a racehorse.

Other shapes and flexibility to decor: a quarterround cocktail table between two chairs or incorporated in a modular setting. Another setting makes a "b" or a "d" depending on the way it is turned. The table is especially attractive and convenient for uniting a conversation group, providing easy access to chair and sofa sitters, yet without the bulk of a huge square.