Isaac Stern ended his anniversary series with the National Symphony Orchestra last night in a blaze of Brahmsian glory.

Before intermission, he gave the Chausson Poeme every ounce of scented passion, yet touched each of its lilac-tinted phrases with the restraint inherent in the score. Leonard Slatkin, the evening's guest conductor, having led Mozart's Haffner Symphony with elegance and style, particularly in the two final movements, gave Stern model support in the somewhat elusive Chausson.

But the towering finale, not only to the evening but to the entire set of five memorable concerts, was a performance of the Brahms Concerto that lit fires through the mounting power of Stern's total domination of the music. Earlier, that command had carried Stern through an imperious opening movement, including a cadenza that came off like a Brahms Capriccio. Nowhere in these concerts has Stern been more at one with the body as well as the spirit of the music at hand. His Guarnerius sang in the ineffable slow movement with that lustrous tone that is uniquely Stern. Slatkin made a flawless partner at every point. The audience shouted after the first movement, and louder and longer after the finale. They were right.