Music must be alive and doing well in this country if young musicians vie for the privilege of giving up their holidays in order to practice their art. Saturday night a group of them who have been doing just that came to the Kennedy Center to show off the results. Chosen from around the country to form the New York String Orchestra, they turned in an impressive performance under conductor Alexander Schneider.

Ranging in age from 15 to 22, these players have been participants in a special end-of-the-year project, now in its 13th year, known as the New York String Orchestra Seminar. For almost two weeks they are immersed in chamber music sessions and orchestra rehearsals under the guidance of Schneider, who was a longtime member of the Budapest String Quartet, and several other professionals. This intensive music-making culminates in three concerts, two at Carnegie Hall and one at the Kennedy Center.

This year's program offered plenty of challenges and the ensemble handled them with aplomb. Not only did it play with that vivid edge -- especially evident in the opening Corelli Concerto Grosso -- often found in emerging artists, but it also came up with solid insights. Schneider's sure and loving direction seemed to make the youthful sensitivities flower, particularly in the passionate writing of Haydn's Symphony No. 49.

There was virtuosity, as well, of the most satisfying kind. Oboist Douglas Boyd, a soloist with Julie Gigante in Bach's C-Minor Concerto for Violin and Oboe, turned his lines into radiant song, revealing a major gift for eloquence. And a small ensemble made the tricky writing of Stravinsky's "Dumbarton Oaks" Concerto bounce with pert ease.