The St. Paul Chamber Ochestra saved some of its best material for the end of its visit to Washington. A program that began well Saturday night, with Bach's Fourth and Fifth Brandenburg Concertos, managed to show significant improvement in a second half devoted to the music of Stravinsky.

Not that Stravinsky's "Ragtime," his First Suite for orchestra and his "Pulcinella" suite are greater music than Bach's, but on this occasion they had even more impact. The performances were crisp, witty, beautifully articulated and balanced--a carefully controlled riot of instrumental color, directed with a firm and knowing baton by conductor Pinchas Zukerman. This part of the program sounded more thoroughly rehearsed--possibly because it seems to present greater technical challenges than the Bach, but also no doubt because there were television cameras in the Kennedy Center Concert Hall recording the music for telecast early next year as part of a special tribute to Stravinsky.

The Bach concerti were a family effort, with flutist Eugenia Zukerman performing in both works and her husband joining her as a violin soloist. This half of the program climaxed in the slow movement of the Fifth Brandenburg, a long and exquisite dialogue for flute, violin and continuo which shifts the concerto temporarily into the style of a trio sonata. It was magnificently performed, with the flute and harpsichord more clearly audible than in the other movements.

Elsewhere in the Bach works, which have some tricky work for the solo violin, Zukerman managed to hold the performance together as a conductor while shining as a soloist, but the orchestra did not seem quite up to its best performance standard. Flutist Nadine Asin and harpsichordist Layton James, the other soloists in the Bach, both performed well if not spectacularly.

The spectacular moments were reserved for Stravinsky, particularly "Pulcinella," with styles ranging from the baroque concerto grosso to the modern circus band. Everything was right in this music: the rich sound of the minimal number of strings, particularly in the bass; the beautifully blended and balanced winds, played at a virtuoso level; the mercurially shifting spirit of the music from delicate serenade to brash, brassy satire. The same virtues could be heard in the Suite and particularly in the "Ragtime," which generated a splendidly jazzy feeling.

The St. Paul ensemble should look forward to a warm welcome on its next visit.