Tony Roberts, one of America's most versatile actors, believes that a long career in the theater is often a matter of being rediscovered.

It has been 27 years since the ever-youthful, curly-topped Roberts made his Broadway debut in Dore Schary's short-lived "Something About a Soldier." Since then he has starred in more than a dozen long-running Broadway shows and a score of films, including the recent "18 Again!" with George Burns.He plays Burns' son and the father of Charlie Schlatter, with whom the 92-year-old Burns changes bodies. It's another comedy role for Roberts, 48, who set out to be a Shakespearean actor, but he is philosophical about it.

"George Burns has mythological status and you can't help learning a lot about being a professional from an actor like that," Roberts said. "And I think Schlatter is not only a good actor, but a wonderful kid for whom I feel tremendous affection."

Roberts also has appeared on television, most recently as social climbing Sloan Thorn in the ABC sitcom "The Thorns," which ran earlier this season.

Only when Broadway, Hollywood and TV assignments have allowed, has he been able to follow his dream of a career in the classic theater by starring in Shakespeare and Chekhov productions in leading regional theaters.

Son of radio and TV announcer Ken Roberts, the New York-born actor is a graduate of Northwestern University's theater department where he studied with Alvina Krause, "a teligion."

"I come from idealistic origins. My earliest ambition was to be an American Laurence Olivier, a great Shakespearean actor or at least 75 percent that and 25 percent Gene Kelly and the Three Musketeers," Roberts said with a smile.

"I didn't particularly think of myself as a comic actor, but that's the way it's developed over the years. But I still think a great performance of Shakespeare or Chekhov is the finest thing an audience can have. It's a transcendent experience, but unfortunately we don't know how to do it from the word one in America.

"We don't have the training and the tradition and when it comes right down to it, classic theater isn't successful in the American marketplace. We ought to have a subsidized national theater and an attempt on the part of professionals to perfect a classic style.

"Joe Papp's New York Shakespeare Festival takes a quantitative rather than qualitative approach. The British come here and do it for us, and that makes me jealous. We're an English-speaking country and doing nothing to make Shakespeare accessible to people."

With regard to the inevitable slow periods every actor experiences, Roberts is equally philosophic.

"There are slow periods in any career in the theater, but if you stick around long enough, you'll get discovered again," he said, pointing to his recurring career in the musical theater as an example.

Years after his last musical on Broadway, Beverly Sills invited him to appear in the New York City Opera's revivals of "Brigadoon" and "South Pacific." He recently played Sky Masterson in "Guys and Dolls" for the Pittsburgh Light Opera.

"I love working with the New York City Opera because it's a wonderful company setup with a cast of people who have worked together for years," he said.

"It's so unlike the theater. There is no backbiting. The cast knows just how long the show will run and they will go on to other things afterward. There is a feeling of security rare in the theater.

"I went into musicals when they were the only thing going. I always had a good ear and could sing enough to get by, but I am not a singer. I am an actor who can sing. My greatest success was in the Neil Simon-Burt Bacharach musical, `Promises, Promises,' for which I won more votes in the London Critics Poll than Olivier and Carol Channing."

Roberts prefers the stage to films, which he describes as "really silly, with no relation or bearing on being in a play."

"In films, there is no communication with an audience. You have to survive the tedium of all that waiting for a minute or two of camera time, then the shot may not be successful because of a boom shadow or the sound of a plane. The stage is real. It has immediacy and a beginning, middle and end."

Roberts has worked more with Woody Allen than any other film director, most recently in "Hannah and Her Sisters" and "Radio Days."

"No one in Hollywood has the power he has - the power not to compromise his own vision," Roberts said of Allen. "He is not interested in the commercial aspects of his art. As an interpretation of the vision of one creator, Allen films are the purest movie experience you can have."