They might have problems with Tchaikovsky, but when the agenda is Haydn and Mozart, as it was last night in the Kennedy Center Concert Hall, you would have trouble finding more appropriate performers than the Mozarteum Orchestra of Salzburg.

It is a chamber orchestra with a maximum of 42 players, at least on its current American tour. Under the skilled baton of Hans Graf, it was as light and agile as we expect a chamber orchestra to be, but its tone last night had a richness and power usually associated with ensembles twice its size.

With only one or two lapses in the whole evening, the Mozarteum Orchestra played with the assurance of artists engaged in their specialty. Salzburg is, of course, the post card-pretty town where Wolfgang Amadeus Mozart was born, and in the last century particularly it has become a lively shrine to his memory. It is the scene of one of Europe's great summer festivals and of intensive musical activity at other times of the year as well.

The Mozarteum is the world's leading center of Mozart studies and a conservatory that attracts gifted young performers from around the world. The Mozarteum Orchestra had already been around for nearly 40 years when the conservatory was founded in 1880, and its tradition goes back far beyond the summer festival, established in 1920, where it is the resident orchestra.

So when the music is Mozart, or any Austrian music of the 18th century, the Mozarteum Orchestra plays with the special authority of musicians swinging into down-home styles. The concert opened with a dazzling performance of Haydn's Symphony No. 97 in C -- a bright, energetic, cleverly inventive testimony to the composer's high spirits on his first trip to London when he was 60 years old.

The final work, Mozart's great 40th Symphony in G minor, rightly provoked a nearly ferocious torrent of applause, and after long standing ovations conductor Graf led two encores: the brilliant, boisterous and colorful last movement of Carl Maria von Weber's First Symphony and Mozart's "Col Legno" March, in which the string players turn their bows around and play with the wood rather than the horsehair.

There had been one bad moment in the third movement trio section of the 40th symphony: The horns went off key, just for a split second, and then settled down. This, and the first movement of Mozart Fourth Violin Concerto, K. 218, were the only places where the players showed human frailty.

The soloist in the concerto was 19-year-old Austrian violinist Beni Schmid, a graduate of the Mozarteum and obviously a spectacular young talent but one that still needs a bit more seasoning. In the first movement, Graf set a pace that did not seem to please Schmid; his tone grew edgy and he seemed rushed and bothered until the cadenza, when he played a long, at least partly improvised solo. Suddenly, he was relaxed; his tone grew warmer and his technique more self-assured.