"Who is that woman in the purple veil?" asked Walter Hopps, National Collection of Fine Arts curator and art guru about town, gazing across the room. It was Suzanne Codi, talking to friends and blinking animated gray eyes under her thrift shop veil. He went over to meet her. (She told him they had already met.) "You look smashing . . ." he said.

And so did many of the other 500 guests who turned out Saturday night in satin, tails and grandmother's dancing shoes for a benefit for the Washington Project for the Arts (at $10 a head). The downtown G Street multi-story gallery threw open the back alley between its building and the dark red brick of Sloan's, putting the big band sound of Bob Israel and the Washington Jazz Battalion at the far end of the alley, framed by the silhouettes of downtown buildings against the sky.Wasn't this the scene from "West Side Story"? They put out strawberries and cherries, ordered up perfect night weather, and had a party. "It's about time, said Alice Denney, head of WPA when it opened five years ago as an alternative gallery, "That they had a fund-raiser like this."

Artist Robin Rose put an arm around his former Florida State classmate, WPA director Al Nodal, and told him to take up art again. "Hey you ought to have a show," said Rose to Nodal, whose blue jacket, black baggy pants, and little bow tie made him look like he was on his way to his senior prom. "Just do one," insisted Rose. "Give yourself a wall. Forget about nepotism -- get a pseudonym."

Artists and non-artists all mingled because art galleries are simply not that big, although WPA is a labyrinth of levels to weave in and out of. Susan Mumford, singer with Tiny Desk Unit, a New Wave group which was to perform later, sized up the crowd. "I thought I was coming dressed up," said Mumford whose hair is flaxen blond on one side and brown on the other.

All came speaking high of WPA.

"I want WPA to stay in business," said artist Janet Saad-Cook with a grin, "because I'm supposed to have a show here."

"I knew I'd see a lot of artists," said gallery owner Chris Middendorf, surveying the dancing in the alley, "but I see some art collectors too -- I mean serious art collectors."

Like John and Nancy Barnum, who came by after a serious dinner party. Both are on the Committee of 100, WPA's group of sponsors and artists who contributed to and planned the fund-raiser for the nonprofit gallery. Artists donated work for the benefit auction planned for Sunday afternoon.

"We are very eclectic," said John Barnum, who is a lawyer. "We only buy what we like." The Barnums have bought some work by artist Joe Shannon, who contributed to the auction. "We've followed relatively unknown artists for years. There's an interesting cross-section of known and unknown shown here."

Artist Stephen Ludlum, in jeans, with beer, scrunched up on a stairway landing next to sculptor Saad-Cook in slinky low-cut purple, sipping white wine. "Everybody's been asking me 'where's your piece for the auction?' Auctions are kind of tempura. I feel kind of snooty about them. Besides, I've given them $12,000 worth of work. I gave WPA a print. It's downstairs. If you really want to see some unique art . . ."

"My sculpture's the best," piped up Saad-Cook who has contributed to the auction. "It's an antique box wrapped with gauze. I do a lot of gauze."

After midnight, big band gave way to New Wave with Tiny Desk Unit. But gallery owner Jack Rasmussen was just as happy with big band. "I absolutely detest the '50s," he said to Al Nodal. "I'm glad we're going back a little."