There was a flower shower on Sunday afternoon at Carnegie Hall when the conductor Mischa Santora concluded his last concert as the music director of the New York Youth Symphony, a post he held for five years. Mr. Santora had just led the eager players in a confident and affecting performance of Brahms's ''German Requiem,'' with two fine soloists, the soprano Lauren Flanigan and the baritone Zheng Zhou, and a combined choir from the State University of New York at Buffalo and Queens College (directed by Harold Rosenbaum).
In tribute to their conductor, the seated players, some 100 strong, pounded their feet on the stage so vigorously that the technical crew at Carnegie Hall may want to check out the support beams. Then, when Mr. Santora appeared for his final bow, along with the soloists, the grateful musicians took pink flowers they had been hiding on their music stands and tossed them at the lanky, young maestro -- an easy target at 6 foot 5.
This may seem just a sweet story of a respected educational ensemble paying homage to an emerging conductor who has done some valuable work. But looked at a certain way, the New York Youth Symphony does a better job than many top professional orchestras of addressing critical questions confronting the classical music field.
At a time when every performing arts institution is compelled to define a mission, the Youth Symphony has a clear one: to provide tuition-free programs in orchestra, chamber music and composition to musicians ages 12 to 22 from the New York City region. It also, admirably, presents standard repertory works in fresh ways that engage performers and audiences. After all, most of these musicians have never played these works before and are thrilled to be doing so. Their excitement more than makes up for any limitations in execution.
What about enticing new listeners into the concert hall? Every year new pools of appreciative parents, siblings and friends show up at Youth Symphony concerts. Finally, through its First Music project, the orchestra champions new music. Every program includes the premiere of a commissioned work from a young composer. On Sunday it was a vibrant performance of ''Mosaic'' by John Kaefer, 25, the 54th composer to be commissioned through First Music. ''Mosaic'' is a vividly scored, 12-minute work of primordial growls and gnashing outbursts, with fleeting moments of delicate colors and undulant riffs. The project teaches that playing new music is as central to what musicians do as playing Brahms.
Some youth orchestras are led by veteran conductors long experienced in working with educational ensembles, certainly a valid approach. The New York Youth Symphony prefers to recruit gifted young conductors eager for the opportunity, like Mr. Santora.
Born to Hungarian parents who are musicians, Mr. Santora, 30, grew up mostly in Lucerne, Switzerland. His musical studies took him to Berlin and then to the Curtis Institute in Philadelphia. He was about to enter a graduate program at the Yale School of Music when he got the job with the Youth Symphony and moved to New York.
''It was too good an opportunity to turn down,'' he said in a recent interview.
''You only learn early on by being out in the profession,'' he added. The Youth Symphony is an education for everyone, he said, ''not just the musicians.''
Mr. Santora has also been busy elsewhere. He is in his second year as the artistic director of the respected Cincinnati Chamber Orchestra and has had guest appearances with orchestras in the United States, South America and Europe. Yet he has benefited greatly from working with talented student musicians, he said, for ''in orchestra playing the basic problems are always the same: rhythm, sound, phrasing, balance, articulation.''
There are, though, some real challenges specific to training ensembles like the Youth Symphony. One is the need to rotate principal players, especially among the winds and the brass. Like a coach of a high school sports team, Mr. Santora has had to balance a desire to give all players a shot with the goal of giving the best performances possible.
Another challenge is the rehearsal schedule. Because the players have busy school lives and come from as far away as Connecticut, the orchestra can rehearse only once a week: Sunday afternoons for four hours. More frequent rehearsals of shorter duration would be more effective. ''Some good work can get lost in a week's time,'' Mr. Santora said. But dealing with the schedule has taught him efficient rehearsal techniques.
That efficiency was evident in Sunday's concert. Brahms was a theme of this season's three concerts. This last one began with a spacious account of Brahms's ''Song of Destiny'' for chorus and orchestra. The ''German Requiem'' is a profound and unusual work that conveys grief over loss, yet offers comfort to the living. Though Mr. Santora, his players and the well-drilled choristers captured the music's bleak sadness, the youthful energy that charged the work's exuberant sections emphasized the requiem's subtext of optimism.
While Mr. Santora is maintaining his New York base and his Cincinnati post, he will be working in Europe during the next few months. The Youth Symphony opens its 40th season in December with a new music director on the podium: Paul Haas, 31, of San Francisco, trained at Yale and Juilliard, currently working with youth orchestras in San Antonio and eager to be coming to New York.