Maestro will pass baton to up-and-comer in '09

Salonen, who will still live in Los Angeles, intends to concentrate on composing, although he plans to continue to conduct the Philharmonic and other orchestras.

"I always felt that one day I would have to make the change in my own life, bite the bullet and see what it is to be a composer who conducts rather than the other way around," he said in an interview.

"There is nothing drastic or dramatic behind this," he said. "I would say it's something quite normal or organic in my case."

Already nearly as in demand as a composer as he is as a conductor, Salonen, 48, said he had long wanted to find more time to write. But his scheduled departure will still make him the longest-serving music director in the history of the Philharmonic, which was founded in 1919.

Signing Dudamel to a five-year contract as its next music director, beginning in the 2009-10 season, is a daring move by the orchestra. Audiences instantly respond to his ebullience and his curly-haired, boyish good looks. Yet although several major orchestras are believed to have been vying for him, Dudamel had never stood before a professional orchestra before taking part in a conducting competition sponsored by the Bamberg Symphony in Germany three years ago.

He was hailed as a natural on the podium and easily won that competition. Former longtime Philharmonic General Manager Ernest Fleischmann, who was among the jurors, told The Times in December: "Of the hundreds of conductors I've come across, only a few in their early 20s were of his caliber. Two others were Esa-Pekka and Simon Rattle, now music director of the Berlin Philharmonic."

Dudamel's U.S. debut was conducting the Los Angeles Philharmonic at the Hollywood Bowl in the summer of 2005, and it proved an immediate sensation because of the electricity of his gestures and his unbounded enthusiasm.

Since then, he has conducted some of the world's most important orchestras, including the Boston Symphony, and has conducted at Italy's La Scala opera house. Next season, he is scheduled to make his debuts with the New York Philharmonic, the Berlin Philharmonic and the Vienna Philharmonic. He has also been signed to an exclusive contract by the Deutsche Grammophon record label. On Thursday night, he led the Chicago Symphony for the first time.