The New York Youth Symphony, now in its 34th season, seldom has trouble filling Carnegie Hall for its concerts. Sunday afternoon's was no exception. Naturally, there were many families of orchestra players in attendance, who were fairly easy to spot: you see children pointing excitedly to brothers and sisters onstage, and alert parents nudging each other during a clarinet solo or a timpani outburst.
But these concerts have always attracted listeners who simply want to hear exciting, unjaded music making, and this one provided it. Nothing makes an overplayed repertory work seem fresher than a performance by musicians just discovering it.
Such was the case with Tchaikovsky's ''Romeo and Juliet.'' The youths in the orchestra range in age from 12 to 22, and their level of technical and musical accomplishment is remarkable. Their conductor, Miguel Harth-Bedoya, had some trouble getting his players to keep the intensity alive in the ruminative introductory phrases of the Tchaikovsky. But the musicians tore into the tempestuous episodes with abandon, and the famous love motif was archingly shaped. All the playing lacked was several million dollars worth of top-quality instruments.
There was also the world premiere of a piece commissioned by the orchestra, ''Tongues of Melting Light,'' a seven-minute tone poem by Jason Uechi, a 28-year-old composer completing a doctorate at Columbia. The work, which evokes sunsets in the composer's native Hawaii, tries to express opposing forces of day and night in music of unstable harmony and stark contrasts: skittish repetitive figurations are cut off by thwacking percussion volleys, which lead into shimmeringly quiet sustained harmonies, and so forth. I can't say I envisioned sunsets. The real inspiration seemed to be a roster of composers from Debussy to Ligeti. But the piece is richly colored and skillfully orchestrated.
The main work was the Dvorak Cello Concerto with Alisa Weilerstein, a 14-year-old cellist from Cleveland, as soloist. My qualms about the exploitation of prodigies vanish when I hear an enormously talented musician like Miss Weilerstein playing with an orchestra of peers. The performance was a nothing-to-lose adventure. Miss Weilerstein played this touchstone work with boldness, assured technique and vibrant tone. And the orchestra under Mr. Harth-Bedoya was with her all the way.
Miss Weilerstein has also performed with the Cleveland Orchestra, which is more worrisome. But for now, she is full of promise. The New York Youth Symphony has a good track record of presenting young talent. At its very first concert a 17-year-old violinist named Itzhak Perlman was the soloist.