New symphony orchestras of more than 100 players do not spring into being every day or even every year. But two years ago a Sri Lankan conductor named Rohan Joseph, who now lives in this country, had a vision of just such an orchestra.Last night the results of that vision were heard in the Kennedy Center debut of the American Philharmonic Orchestra.

The players number around 114, with an average age of 28. They come largely from the pool of highly skilled musicians who abound in and around New York City. Under his direction they gave the Washington premiere of a Yellowstone Overture by Richard Adler, accompanied the incomparable Lili Kraus in Mozart's A Major Piano Concerto, K. 488, closed off the first half of the concert with Brahms' Academic Festival Overture, and ended the program with the Third Symphony of Bruckner.

The new orchestra, which by now has three Carnegie Hall concerts under its belt, has a limitless potential. If the musicians make some raw sounds now and then, they also turn out some passages of great beauty. The talents of the players, section by section, and among the soloists are of a very high order. But they suffer from limited rehearsals and severe economic hazards. They came to Washington yesterday by bus and returned to New York last night the same way. If they were lucky, they got home around five this morning. That is not the way great orchestras live.

Thanks to Lili Kraus, the Mozart concerto was the musical peak of the concert. Her playing was totally informed in style, with beautifully shaped phrases composed of singing melodic lines and spirited rhythmic vitality. The orchestra was twice too large for a Mozart concerto, but the playing was good. Responding to the audience's enthusiastic applause, Kraus said, in reference to the orchestra, "I feel like a fairy godmother at the birth of a new child."

Adler's Yellowstone Overture, inspired by the Grand Canyon, is no threat to Ferde Grofe's memorable suite. Such banality!

Joseph tends to ask his orchestra to play loud and louder too much of the time. There were few contrasts in the Brahms or Bruckner beyond those of the most immediate nature. And the Brahms turned vulgar at the close in such a way that the audience broke into the music before it was ended in a manner that may experienced conductor automatically avoids.