Leonard Bernstein spoke loudly and carried a small stick.

"What's the matter. Are you afraid?," he beckoned to the nervous youths interspersed among the accomplished members of the National Symphony Orchestra. "Get rid of your inner fears, anxieties and despairs," the maestro commanded. "Just play."

It was Youth Orchestra Day in Washington. As usual, Bernstein was at his best. Having popularized classical music with the televised "Young People's Concerts," the master composer and conductor arrived at the Kennedy Center Concert Hall yesterday with the unabashedness of a Luke Skywalker, breaking his baton during the first two minutes on the podium.

The intensity was contagious, and the emotion generated by the sight of a 62-year-old man, flying through the air on a crest of music, was enough to bring tears to the eyes of some older musicians. Aiming for key notes, Bernstein used his singing voice to interpret the countours in Beethoven's "Egmont Overture," and by doing so led the talented, but tenderfoot, musicians safely through the complexities of this haunting and noble tragedy.

"This man is incredible," said Philip Swaby, a 16-year-old violinist, and student at the School Without Walls in Washington. "He's got so much energy he obviously doesn't let anything stand in his way.I wasn't really scared because there's safety in numbers when you work with a guy like that."

About 70 students from area youth orchestras -- representing the District, Northern Virginia, Prince George's and Montgomery counties -- participated in the special event. Each year, members of the youth orchestras join members of the National Symphony for rehearsals and coaching sessions. The program includes rehearsals with famous guest conductors such as Bernstein and an annual concert with Exxon-Arts Endowment Conductor Hugh Wolff, who is 27. a

The orchestra also included youth fellowship students who take music lessons from symphony members. The fellowships are provided by the D.C. Commission on the Arts. Yesterday's program was just one of several music education events sponsored by the National Symphony and the John F. Kennedy Center for the Performing Arts.

Among those seated in the audience for Bernstein's session was Sen. Edward Kennedy, a longtime Bernstein friend who arrived to have lunch with the maestro. As usual, Bernstein's rehearsal with the youths was running late -- about 15 minutes this time -- when it was brought to Bernstein's attention that his guest had arrived.

"Out of time? Oh God, there is never enough time," he groaned, as he stomped the podium. Then he raised his broken baton. And the band played on.

"That's quite all right," Kennedy shouted. "I'm really enjoying this."

Sweat began streaming down Bernstein's face. One second he looked like a craggy-faced ogre, the next like a saint about to make his ascent.

"This in not sexy stuff," he told his orchestra. "This is Beethoven."

"You learn a lot of little things, said Natalie Jankowski, an 18-year-old McLean High School violinist who sat in front of Bernstein. "There is so much energy it actually helps you relax. He makes you want to do something."

"It's just fantastic," said Carol Brown, a music student at Catholic University. "Working with the experienced players helps you improve your technique and style. You learn to listen better."

"All I can say is that watching him brought tears to my eyes," said Jackie Anderson, who plays second violin with the National Symphony. "And I'm very impressed with the youngsters. They are very self-assured, very confident. I would have been terrified."