It could have been the opening of a group show anywhere: white wine in plastic cups, perspiring friends and a smattering of red "sold" stickers on the walls.

But the artists packed into Alexandria's Firebird Gallery Tuesday night had something special about them. Beyond the art--which at its best was very fine--were some extraordinary re'sume's.

Tony Ywain, wearing an "Aspiring Artist" T-shirt, began his art career in jail in Arlington; Quinton Nalle, trained at the Corcoran, has spent most of his young life battling sickle cell anemia in various hospitals. And featured artist Shirley Brown, after several tough years, now lives at the Lady of Mount Carmel Shelter in downtown Washington.

"We try to provide a market for the many talented people who have had an institutional experience, or a handicap of some sort which keeps them from fitting into the mainstream,"says Dennis Roach, director of the nonprofit gallery founded three years ago by the National Center on Institutions and Alternatives, which focuses on alternatives to prison or confinement in institutions. .

Of the 15 artists selected for this first show in Firebird's new space, one is handicapped, five have been in mental institutions and some of the rest have been in penal institutions, according to Roach.

"But the artists come first; the background is secondary," he says.

Sometimes background is secondary in the art as well, though it can be highly relevant. James Ferine, from Yonkers, N.Y., was an accomplished sculptor before he suffered a nervous breakdown in the early '70s. He now seeks to relate a sense of that experience via soft figurative sculptures with clay masks, and he succeeds powerfully.

Background is masked in the work of Shirley Brown, who has a whole gallery devoted to 24 of her charcoal and ink drawings, along with more tentative experiments with oil and watercolor. Subjects are varied: small landscapes brushed with black ink, street scenes and tiny drawings of old sailing ships. But Brown's best drawings are of birds and animals, with which she seems to have a very special--and occasionally sentimental--relationship. "Those seals would make even a seal hunter cry," noted one guest.

There also are some extraordinary freewheeling drawings of birds in which the shapes and forms have been captured sparingly, unerringly, instinctively. One such drawing, "Red Bird," is of a kestrel, says Brown, "the most gifted of birds." According to friends, the artist has adopted and cared for several injured birds in downtown parks.

But most compelling among these works is a drawing of a turtle, titled "Be My Friend," boldly rendered in sweeping strokes with the side of a piece of charcoal. A figure wrapped in a coat seems to be feeding it bread.

"Did you ever see a turtle cry?" Brown asks. "Animals cry, you know. I was living in an apartment hotel in Philadelphia once, and someone left a little turtle alone in a box. I looked at him and saw real tears. I took him down to the water and let him go. I let an experience like that influence me."

A slim, thoughtful and dignified woman with graying red hair, Brown says she has been drawing since her childhood in Buffalo, but without formal training. "This is my first show," she says, "and most of the work in the gallery is from the last three years--an accumulation of work that I saved. It's something I just did when I was growing up, but never did much of it. I just liked to do some drawing. I haven't had much schooling--you know how it is when you have some talent, or a gift."

A gift she has, and with luck she will be able to fulfil her next dream of taking a painting class somewhere.

"I haven't made any art for a year, but I'll get back to it," she says. "If you're in the world by yourself, you make drawings and carry them around, but who are you going to give them to? Finally, somebody wants them."

Brown's drawings are priced from $10 to $200 for her turtle. They will be on view at Firebird Gallery, along with the rest of this show, through June 30. The gallery is at 814 North St. Asaph St., on the edge of Old Town Alexandria. The gallery will be open today from 9 a.m. to 5 p.m. Otherwise, gallery hours are 9 a.m. to 5 p.m. Mondays through Fridays, or by appointment at 684-0373. Landscapes at Tolley Galleries

For three years, Tolley Galleries has sponsored a National Landscape Competition, offering $600 in prizes to painters working in traditional realist modes. This year 70 artists sent slides in response to notices placed in American Artist magazine and on art school bulletin boards. Fifteen finalists--24 paintings in all--were selected by George Washington University art professor Arthur Hall Smith, and are displayed at 821 15th St. NW.

Though artists from Massachusetts to Georgia are represented, most are from this area, including the best of the lot--Arlington resident Charles Z. Szczepanski. A Polish-born portraitist and muralist, he studied at the Ecole des Beaux Arts in Paris. He is represented here by a broadly brushed, richly colored "Sunset on Sugar Lake." Retired Army officer Carlo Biggio has painted a luminous angled view of an old railroad station at Point of Rocks, Md. Christine Lego's small impressionistic views of the Baltimore Harbor, and David Zimmerman's strong rendition of Rockefeller Dome, Ariz., are also noteworthy. The show continues through June, and is open Mondays through Fridays, 10:30 a.m. to 5:30 p.m. l