"Who are these people?" asked Ira Sabin, publisher of Jazz Times, as he surveyed the crowd of White House aides, congressmen and network television correspondents at the opening of Charlie's Georgetown.

It wasn't exactly a jazz crowd at Charlie Byrd and Pete Lambros' new night spot facing the Georgetown waterfront. Cathy Douglas, widow of Supreme Court Justice William O. Douglas, busily led a team of volunteer waiters and waitresses, including Rep. John Burton (D-Calif.), White House Social Secretary Gretchen Poston and Rear Adm. Taze Shepard.

"A lot of us were waiters and waitresses when we were in school," she said, while balancing a tray of drinks. "I was a waitress when I met the justice."

Someone came by and asked for a gin and tonic. "Business is good," she shouted while knifing her way through the crowd, "But tips are bad."

Also wearing the specially made aprons for the volunteer waiter corps were Tyler Abell, Henry Catto and Lloyd Hand, all former chiefs of protocol.

A crowd of about 700 jammed the club complex, washing down shrimp, oysters, clams and meatballs with an endless variety of drinks. Inside the main dining room a crowd listened to jazz combos.

Ron Nessen, White House press secretary in the Ford administration and an investor in the club, stood outside the main dining room greeting colleagues he knew from his reporting days at NBC.

"Welcome to the bar," he said, pumping the hand of ABC-TV correspondent Steve Bell. "It's everybody's Walter Mitty dream to own his own bar."

Roger Stevens, chairman of the Kennedy Center, said, "It shows Washington is jumping. I like to kid people from New York that we're not a hick town anymore."

Shortly before going on stage in the main dining room for a 10-minute performance with fellow-guitarist Herb Ellis, Byrd said, "There's more to this place than the music. We'd like to make this a nice, relaxed place for everybody."

For Byrd and Lambros, the club is the fourth time around. The team of guitarist and manager is trying its luck this time in a comfortable four-room center for dining, dancing and jazz in Georgetown.

The club opens to the public tonight.

Byrd and Lambros, who made a go of it alone in their previous clubs, the Showboat Lounge and Byrd's Nest, are doing it this time with a host of investors and limited partners, including lawyer Robert Martin, a Truman administration aide; builders Robert Safer and Barrett M. Lindie; Nessen, and Bess Abell, Joan Mondale's staff director.

"We're going to try what everybody wanted to do and didn't succeed," said Lambros. "We want to combine good food and good music."

In what will be the first jazz spot of its caliber in the city, the $600,000 establishment will feature four different rooms: the 140-seat main dining room, the Riverfront Piano Bar, Charlie's Backroom and the Veranda Cafe. Also, there will be a raw bar and the Plum 2 Art Gallery (the latter will feature paintings and sculpture by local artists).

The menu will be highlighted by continental dishes and American food. "We want to make this place comparable to classy clubs like the old London House in Chicago or the Embers in New York," he said.

The musical emphasis will be on easy-listening fare. Opening tonight will be guitarists Byrd and Herb Ellis. Others scheduled, said Lambros, are the piano-playing priest, Father Tom Vaughan, and trumpeter Don Goldie.

"It's silly for me to sit around the corner from Blues Alley and book Zoot Sims with a local rhythm section," said Lambros, who's been a part of the Washington jazz scene since the 1950s. "I'm looking for unusual acts.We plan to use a lot more local musicians than we did before. Maybe people like Clea Bradford. And on Monday nights we might have a Dixieland group come in once in a while."

Other unusual bookings, he speculated, will include pairing pianists Teddy Wilson and Dave McKenna or vocalists Helen Humes and Carrie Smith.

Byrd, who had a major hand in starting the bossa nove craze of the 1960s, will perform at the club 20 to 26 weeks a year, according to Lambros, who also serves as manager for the guitarist and Phil Woods, Barney Kessel and Ellis.

Byrd and Lambros got their jazz-club start with the old Showboat Lounge at 18th Street and Columbia Road, NW, in the 1950s. They closed that club in 1967 because of a deteriorating neighborhood and no room for expansion. They opened Byrd's Nest in Silver Spring in the same year. But two years later it closed because customers found it hard to get to. In 1976, they tried a second Showboat Lounge, this time in Silver Spring. But it too closed after two years. The performers got too expensive.

So Lambros and Byrd, longtime optimists, are trying a jazz club again. Only this time their musical hopes aren't so high.

"I've been through that thing with the high-price artists," laughed Lambros. "We want to do something different. But in this case we've got a little bit of something for everybody."