MARK NELSON ON PLAYING EINSTEIN

Mark Nelson knew that it would take more than a head full of hair gel to play the young Albert Einstein in Steve Martin's Off-Broadway comedy Picasso at the Lapin Agile.

"In most cases I come into rehearsal with everything planned out, but I struggled with this role," says Nelson. "My friend George Segal really helped when he told me, 'All you have to do is keep out of the way and let Einstein give the performance.' " It worked: Nelson collected a stack of terrific reviews for his witty, assured work in the hit play.

Martin imagines a meeting between Einstein and Pablo Picasso (Paul Provenza) in a Paris bar in 1904, before either man had achieved international success. Optimism reigns as the bar's patrons trade stories and dreams for a new century.

"It's a treat every night," Nelson says of the play, "and great therapy, too, because this character is so full of joy. Even if I'm in a bad mood when I start the show, he always carries me to a healthier state of mind." He adds, "Even though the play is incredibly light and fun, it's a substantial comedy. To me, it's about being open to the big things that are happening in the world instead of getting stuck in your own rut. I love its soulfulness and yearning and off-the-wall eccentricity." Over a light lunch in his Upper West Side neighborhood, the friendly, down-to-earth actor talked about his own creative quest in a profession filled with uncertainty. Born into a family of doctors and teachers, Nelson grew up in suburban New Jersey and graduated from Princeton. "I always desperately wanted to be an actor, but my parents were terrified of the idea," he recalls. "I started college thinking that I would become a teacher or a therapist."

Instead, he took drama courses and dreamed of performing at Princeton's McCarter Theatre. A term paper on The Dybbuk led to his first professional job in a production of the play directed by Joseph Chaikin. "After that, it was a short step to the glory of restaurant work," he says. And yet Nelson quickly became a regular presence on the New York stage, equally adept at comedy (including four Neil Simon plays) and drama (A Few Good Men). He made it back to the McCarter, too, in The Three Sisters and two other plays.

Though his current success brings talk of movies and television series, Nelson is determined to enjoy the play without dwelling on what it might lead to. "Sometimes I get envious that I haven't had the career others have, but when I see things in perspective, I realize how incredibly blessed I've been," he says. "A colleague of Einstein's said a beautiful thing in one of the documentaries I watched. He said that when Einstein was working on something, he had no sense of time running out. Most of us think, 'I'll give a year of my life to this, and if it doesn't work out, I'll move on.' Einstein never cared how long the path might be; it just mattered that he was on it. That's a wonderful lesson."

Nelson laughs as he recalls being serenaded in the rehearsal hall last fall on his 40th birthday. "If you'd told me when I was 20 that I was going to be rehearsing a play by Steve Martin 20 years later and that he'd sing 'Happy Birthday' to me, I'd have said, 'Then I could die happy!' "

-- By Kathy Henderson