Three years ago, when Pinchas Zukerman compounded the complexities of his brilliant career as violinist and violist to become, in addition, the music director of St. Paul's immaculate Chamber Orchestra, inevitable eyebrows were raised. "Isn't he fooling himself?" waxed the skeptics. "It's one thing to dabble with the baton which Zukerman had been doing for some time and another thing to try this." Even Zukerman admitted at the time that experience with a stick was not his strongest point.

At Saturday night's concert by him and his orchestra at the Kennedy Center Concert Hall, there was convincing evidence that the level of his achievement is reaching a parity with his seriousness of purpose.

The high point was an utterly seductive interpretation of Mozart's Symphony No. 35, the "Haffner." Here Zukerman was conducting a "Haffner" fully worthy of the lofty standards of Mozart playing he sets as a soloist.

Phrases invariably breathed with grace and passion without ever distorting the overall shape of the music. The pulse was gentle, without any suggestion of a lag in the process. Balances and Mozart's exquisite timbres were handled with grace and imagination. In short, it was a Mozart interpretation at a very sophisticated level, something not all that common with American orchestras, and something that is now especially rare at orchestral concerts in Washington. Maybe Zukerman, as he said in an interview last year, may never take on conducting something so gigantic as the Bruckner symphonies, but right now the world needs Mozart conductors more than Bruckner ones.

Zukerman's baton technique does not appear to be a peerless equivalent of his violin technique. But that is only part of successful conducting. And probably the most important single element is the projection on the music of a strong, explicit interpretation. In the "Haffner" there was no question that Zukerman knew exactly what he wanted, and that he was getting it. It comes as no news that the St. Paul orchestra played with great purity and sensitivity.

The other finest moment of the evening came from Zukerman the violinist, with Dvora'k's dulcet one-movement "Romance" for violin and orchestra. It is a gentle chamber work, meant originally as a slow movement for a string quartet that was never completed. In a Victorian way, it is the same sort of piece as the famous Adagio for Strings, originally from Barber's String Quartet; the St. Paul orchestra is also playing that work on this tour. Zukerman's playing was gloriously shaped, with that wonderfully focused and varied tone of his, never sentimental but never chilly.

At first, he conducted Elgar's nostalgic Introduction and Allegro for String Quartet and Orchestra--a warm, rich perfomance.

The remaining work, the Mozart Concerto for Two Pianos with Marielle and Katia Labe que as soloists, was the weakest part of the evening. The Labe ques played well enough, but the clarity of Mozart's lines got a bit blurred by their excessive ritards, their lack of evenness in tone and sometimes excessive pedaling. The interpretation lacked clear focus.