The unexcelled luster and warmth that characterize Isaac Stern's playing when he is in top form were in plentiful supply at his Kennedy Center concert on Saturday night. His bowing arm was at its most assured. That full, rich sound was pure and consistent from the top of the E string to the bottom of the G. Pitch was excellent. Articulation was good. And, also, his sensitivity to style -- from the rigorous severity of Bach to the sensuousness of Faure'.

But there was more.

First, the pianist. He was the eminent French virtuoso, Jean-Bernard Pommier -- no mere accompanist he.

And, second, there was the program. As Stern observed in announcing the encore (the rondo from Mozart's C-major sonata), it was an "evening of sonatas." There were none of the display pieces that almost invariably clutter violin recitals (a little Paganini before your Beethoven, and maybe somebody's variations on themes from "Carmen" afterward). Everything Stern and Pommier played Saturday night was all meat, no fat.

It is as if Stern, now that he is in his sixties, is tired of the old recital ritual. And, being one of the great chamber music players of the day, he has chosen to turn the violin recital into a chamber music event. That would explain the willingness of Pommier, who played a fine solo recital of his own earlier this year at the Center, to join him. To play violin sonatas with the style and e'lan heard Saturday night requires players who are on equal footing.

They must be free, as in chamber music, to challenge and match the nuances of each other. The two men were doing this with as much subtlety in the modest moments as in the grandest ones.

Nothing worked better than the grace with which they were caressing the phrases of the little two-movement Mozart Sonata in E minor (K. 304). That was especially true in the second-movement minuet. For instance, there was a pearly ascending scale on the piano leading back to a statement of the main theme that was colored, both tonally and dynamically, with extraordinary finesse and evenness. Then the exchanges between the two players, each of them imitating the other's phrasing, became addictively deft.

The same kind of rapport occurred in a larger scale work, Faure''s First Sonata in A major (Op. 13), which concluded the program. This is a sonata that requires a balance of lushness with delicacy. There are fireworks, all right, but they must not interrupt the sonata's lyric continuity. (I have heard performances where the two aspects of the work seemed in conflict, the very thing you do not want in a sonata that should be somewhat soothing.)

Stern and Pommier solved the problem by maintaining consistently poised tone, and by keeping the melodic line in clear harmonic focus. The sonata is full of those sustained, full high tones Stern produces that are the envy of any soprano.

An urbane early Beethoven sonata opened the evening, the one in A minor (Op. 23). Its fluency was kept simple, never out of scale -- with, again, exemplary dovetailing of phrases.

Finally, just before intermission, came the peak of the program, Bach's monumental unaccompanied Partita in B minor, one of the masterpieces of the violin repertory, played in a towering manner by Stern. Of the six sonatas and partitas, this is the one that consists of four Baroque dances, each followed by a variation of enormous complexity, both technically and intellectually. The presto variation of 16th notes that followed the courante was so dazzling that the audience interrupted with applause at the end.

This was a model of what violin recitals should be.