Don Giovanni disappeared into smoke, but the cast and 350 members of the audience experienced a more pleasant finale to the opening of the Washington Opera's 30th season Saturday night. The drama and music continued after the show at the Ritz-Carlton, where Washington arts patrons and socialites mingled with the performers for a midnight supper and ball.

Opera star Renato Bruson, who played Don Giovanni, revived from his on-stage journey to hell to attend the party. At the party Bruson managed to maintain his character's seductive charms, kissing ladies' hands and speaking with a thick Italian accent. He said he has played the role many times and it is one of his favorites, but he identifies with the shamelessly manipulative character "only on stage, not in real life."

Cupping his hands against the blaring dance music of Gene Donati's orchestra, Bruson enthused over his first experience performing in Washington. "It is a fantastic cast, a wonderful theater, excellent acoustics."

Dining on salmon mousse, roast duckling with raspberry sauce and souffle glace' Grand Marnier, the guests at the $150-a-plate supper toasted the success of the evening and spoke of the state of the arts in Washington.

Livingston Biddle Jr., former chairman of the National Endowment for the Arts and a board member of the opera, said, "Really my interest is in making the nation's capital here similar to those great capitals of the world -- London, Paris, Rome -- where cultural values are the most important thing . . . Interest in the arts is growing here . . . This capital city is someday going to be a great city for the arts."

Martin Feinstein, director of the Washington Opera, said, "The only complaint I got was that someone asked why we didn't announce the baseball score when Don Giovanni died and went to hell."

Suggested one guest, "You could have put it up on the surtitle screen."

"I was thinking of selling some advertising there," said Feinstein.

Indeed, despite the sparkle and gaiety, the opera company's financial troubles were an unpleasant undercurrent to the evening. Along with the compliments on a fine production, there were frequent pleas for contributions.

David Lloyd Kreeger, chairman of the board, suggested one reason for the economic difficulties. "Opera is for the elite, unfortunately . . . You have to have suspension of disbelief. People are singing instead of fighting. It requires a certain attitude to accept. You need a more sophisticated attitude . . . Unless they're Italian. Then you can get in a taxicab and they'll tell you what's playing and sing the arias."

The production of Don Giovanni faced another peril as well. The scheduled conductor, Daniel Barenboim, became ill and the cast was without a conductor until just about 10 days before the scheduled opening. John Mauceri finally agreed to fill in.

Mauceri was in London, rehearsing an opera at the Covent Garden, and was about to begin rehearsals with the American Symphony Orchestra in New York. In addition, he was trying to recover from a cold. "A week ago Monday I said 'no' . . . I said 'no' on Tuesday, 'no' Wednesday. I said 'no' Thursday. Then at 9:05 Thursday morning I said 'okay.' I didn't cancel one lunch, one rehearsal. I just figured I wouldn't get over my cold until Christmas."

He left the dinner early because he had to fly to New York early yesterday morning, rehearse with the American Symphony and give a concert in the afternoon. For the next several weeks, Mauceri will be commuting between London, New York and Washington, but, he said, "I am happy I can do something. How can you say 'no'?"

Even his health is improving.

"If you apply Mozart to your lungs, things get better."