NEW YORK - Classical music may be a last bastion of formality, but practically everyone at the New York Philharmonic calls its new music director just “Alan.”

Alan Gilbert, a 40-year-old native New Yorker, was introduced Wednesday as one of the orchestra's youngest leaders. He follows what he called “the most exalted conductors of the last 100 years,” including maestros like Gustav Mahler, Arturo Toscanini and Leonard Bernstein.

But none of those musicians was as close to the orchestra as Gilbert. His mother plays in the violin section, his father is a retired Philharmonic violinist and his sister, Jennifer, has played as a substitute violinist.

“I would be lying if I said I wasn't painfully aware - well, let's say aware - that my mother was sitting to my left,” Gilbert joked about the first time he conducted the orchestra in October 2001.

At one rehearsal, he said, his mother started playing a tad late and he reprimanded her with an exasperated “Mom!”

The new music director, who starts his duties in September 2009, was introduced during a news conference at Avery Fisher Hall, the Philharmonic's home at Lincoln Center for the Performing Arts. His parents, Yoko Takebe and Michael Gilbert, looked on proudly.

“It really is the kind of dream I never really dared to have - it's too good to be true,” the conductor said.

Gilbert's appointment ends years of speculation over the successor to Lorin Maazel.

“We have someone who is young and articulate and intelligent and a New Yorker,” Paul Guenther, the orchestra's chairman, said of the Harvard University graduate who has been chief conductor of Sweden's Royal Stockholm Philharmonic Orchestra since 1999.

Gilbert is the first native New Yorker appointed to the position.

“Well, it's about time,” said Philharmonic President Zarin Mehta, adding that Gilbert's three most recent predecessors - Mehta's brother Zubin, Kurt Masur and Maazel - were all “thrilled” with the choice of the younger man for the position.

Gilbert is just over half the age of Maazel, 77, who has said he would leave after the 2008-2009 season.

Gilbert has led the Philharmonic numerous times, proving to the musicians that he is up to the challenge of leading America's oldest orchestra, founded in 1842.

He said his did not yet have an exact idea of what kind of music he would program but promised that it would include everything “from soup to nuts,” from the great classics to “local talents” such as new American composers.

Gilbert has known the current orchestra members since he was a young child, often going on tour with his parents. At the news conference, he recognized several orchestra members in the audience and greeted them by name.

Orchestra members were told of his appointment Tuesday evening when they played a concert in Central Park. Gilbert received “a very emotional outpouring of support,” Zarin Mehta said.

Gilbert is the second-youngest musician to be appointed music director in the orchestra's history; the youngest was John Barbirolli, who was 36 when he succeeded Toscanini in 1936.