Ravel's "Tzigane" is a virtuoso display piece -- brilliant, fast-moving, exotically flavored music that is often chosen by steel-fingered young fiddlers eager to prove what they can do. Isaac Stern, who has not had to prove anything for a long time, dropped it from his program yesterday afternoon at the Kennedy Center and gave his audience better music than had been advertised.

The changes--a complex rejuggling of the program--came after the intermission, when Stern had already played Mozart's Sonata in G, K. 301 and Beethoven's "Kreutzer"--very beautifully and with a gentlemanly deference to his expert partner at the piano, Andrew Wolf. Besides the "Tzigane," he dropped from the program Bartok's Rhapsody No. 1, substituting for both pieces Bartok's First Sonata, which easily equals their combined substance and technical brilliance. He also added his own tribute to the late Nancy Hanks.

In her honor, he told the capacity audience (which included a sizable overflow seated on the stage), "we will play one of Schumann's Fantasiestu cke . . . She was a great friend and a great spirit . . . Her grace, charm, intelligence and vitality enlivened the arts in this country throughout her tenure as chairman of the National Endowment for the Arts." He asked for no applause after this selection, and the audience complied, although with obvious difficulty. It is hard to single out one piece as the best in such a concert, but this was played with a special elegiac intensity that set it apart from the rest of the program.

The only piece played as scheduled after intermission was Szymanowski's "La Fontaine d'Are'thuse," and it was good to hear it--not only because it is seldom played and we are still at the tail end of the Szymanowski centennial, but above all because it epitomized the kind of thoughtful, delicately poised music-making Stern shared with his audience yesterday.

In this work, the Polish composer almost produced something unique: a slow-moving display of violinistic brilliance, one whose effect depends not on acrobatic agility but on the variety of colors evoked and the inner harmonies of their sequence. It was subtly spectacular in a way that one can expect only from an artist like Stern. Bartok's intense, complex and tortuously demanding Sonata followed it without anticlimax, but not many other pieces could have.