"Everything I do is serious," says Victor Borge -- seriously, of course. So why does he make people laugh? Because he's scared; that's why.

Afraid? Victor Borge afraid? For 40 years, as a triple-threat entertainer -- comedian, pianist and conductor -- he has had audiences in the palm of his hand. But he used to worry that they would laugh when he sat down at the piano.

Borge insists that nobody else could do his kind of act without actually copying him: "I use almost all of the possibilities."

He proudly tells of musical accolades from some of the world's best fellow pianists.

But when he discusses the comedy-with-piano that he will be performing Thursday through Saturday at the Kennedy Center, memories and even shadows of fear emerge. The 76-year-old Borge seems relieved that he did not become a regular piano soloist. "It would have been more satisfying in many ways," he reflects, "but it would have killed me.

"Fear. Even today when I play with the orchestra there are moments when I begin to shake.

"The problem that everyone has, be they great or not so great, is that every time you perform, you are defending yourself, proving that you can do it and do it well. You are auditioning every time you touch the piano, because you never know who might be in the audience. The nerves and the fear can take everything out of you and it isn't worth it."

That is about as personal as Victor Borge will get. In spite of his easygoing public style, he chooses, offstage, to be a very private person. He will give an occasional interview, but disapproves of "showing up at cocktail parties just to be seen.

"A performer should have a private life and not share it with the audience," he admonishes. "Share your ability and your art. That is what you have to offer -- what you have for sale.

"If you look in the movies today, you see the big-name people; they don't play parts, they play themselves. The illusion is not as strong. We know so much about the private person, and that is in your mind while you sit there looking at them portraying somebody else."

The son of a violinist with the Royal Opera in Copenhagen, Borge lost his show business illusions early. "I had my heroes," he recalls. "I was in awe of some of those fantastic people until I myself got into the profession. The more I knew about some of them, the less they impressed me on the stage."

Borge developed his entertainer persona during childhood, as a security stage-blanket. "I was taken around, expected to play after dinner on pianos which were generally out of tune -- polished, but out of tune," he says. "This poor kid would have to play Mendelssohn or Schubert on these horrors, so I would talk, make up a composer's name. I would play pieces that I just made up. My father would get angry with me, because sometimes there were very important people in the audience."

His father might have been upset, but audiences loved his clowning. As his routines developed, he began to use them in amateur revues, and eventually polished them to the point where he could make a living as a concert-hall comedian. He also began a career as a movie actor, and won attention for his anti-Nazi satire ("I used to tell people who asked me the difference between a Nazi and a dog that the Nazi raises his arm"). Not all of the attention was favorable. Perhaps because he is Jewish (born Borge Rosenbaum) or perhaps because of his anti-Nazi jokes, he found himself "at the top of the Nazis' public enemy list."

When Germany occupied Denmark during World War II, Borge lost all his possessions, including his piano. He caught the last available ship -- a troopship out of Petsame, Finland, "with only five minutes to spare."

One of the favorite parts of his act used to be when he turned to the audience and solemnly proclaimed: "The Steinway people have asked me to announce long pause that this is a Baldwin piano." He can't do that any more; he now plays a Bo sendorfer, a very expensive European piano noted for its mellow tone and for having more keys than any other piano. So now he jokes about Bo sendorfers.

"They probably had some extra strings and keys left over," he tells his audiences. "Or maybe they didn't count them when they made the first ones. It is the Rolls-Royce of pianos. It has smaller wheels, of course. And I get four sonatas to a gallon of red wine on it."

But he still has fond memories of Steinway, which helped him when he needed it and provided one of the great ego boosts of his career.

In 1940, newly arrived in the United States, penniless and piano-less, Borge sought out the hospitality of the Steinway piano people. "They were very kind, invited me to go down in the basement and practice, which I did every day. I had nothing else to do, except to learn English -- to learn how to pronounce Steinway. As I was practicing one day, the big door opened, a little head stuck through, looked at me and nodded, and the door closed again.

"That happened three or four times during the next week or two. Finally, I asked, 'Who does that head belong to?' 'Oh,' I was told, 'That's Josef Hofmann' one of the great piano players of the century and the former head of the Curtis Institute of Music . I almost fell off my piano stool. They told me that he had made some wonderful remarks about my touch."

Another accolade came at his first comedy concert in London. During a Chopin waltz, a lady jumped up and started applauding. "I thought, 'One of those,' " he says. "At intermission I was told it was Dame Myra Hess. She apparently wanted to show that the musical aspect of my performance was not overlooked.

"This was the closest to my heart that anything can get."

Also close to Borge's heart, and a growing part of his performing career, is his work as a conductor -- in concerts with such fine orchestras as the London and New York philharmonics, the Philadelphia Orchestra and the Boston Pops, and increasingly in the opera house. "To conduct opera," he confesses, "that has been my great desire."

Toward its fulfillment, he has conducted straight performances of "The Magic Flute," and he has his own concert-hall version of "Carmen" -- one that he will be doing next year in London's Covent Garden and says he "would love to do in Washington." In his two-hour condensation of the opera's major musical scenes and dramatic moments, he conducts and narrates with the singers on stage in costume, but with no sets.

"I arrive and begin to talk to the audience, telling them about the composer, humorous incidents." He considers it one of the most important -- and serious -- things he does, helping to build new audiences and bringing good music to people in a form that will not turn them away. Borge says that we may call what he does "popera" -- that is, "opera for people who are afraid of opera."

Borge suggests that "people are afraid and bored because they don't understand. I explain it to them. I present music which is not difficult to listen to, and not too much of it."

But comedy -- the kind of serious comedy he will be performing this week -- is still his best known activity and his defense against stage fright. "I have this reserve," he says. "I can jump up and say something and we can do it over.

"People trust me and know that when I am involved, it couldn't possibly be that boring."