Everything on the National Symphony Orchestra's program Saturday night at Wolf Trap was familiar. Thanks to the ardent ministrations of Mstislav Rostropovich and the intense response of the musicians of the orchestra and pianist Alexis Weissenberg, the evening offered frequent high rewards.

Rostropovich takes the broadest view of Schubert's music, allowing all the time needed to build its long phrases and episodes into twin pillars of instrumental song. He had every detail in hand and the orchestra played with heart as well as admirable polish. Rudolph Vrbsky's oboe, the sound of which is still new to NSO audiences, made outstanding contributions both in the Schubert and the Brahms Concerto later in the evening. As the orchestra's new first oboe, he is a prize of high value.

There was immense gusto in Rostropovich's Beethoven, as well as sensitivity to its wit and good feeling. Question: Why, in both Beethoven and Schubert, were four oboes and four bassoons used, when two of each is all either composer requested? (In the far heavier Brahms orchestra there were only two of each.)

Weissenberg played the big B Flat Concerto of Brahms with full awareness of its craggy size, from an impetuous opening in which he freely let impact rule over niceness in notes, to pages throughout every succeeding movement in which he probed for the inner spirit of the music. His playing rightly recalled the whole corpus of Brahms' piano music: the rhapsodies, the intermezzos, the capriccios. Fleeting arpeggios were matched by thundering scales; the fiendish thirds were tossed off as if they were five-finger exercises. For the poetry of the slow movement, beautifully introduced by John Martin's cello, his tone became a thing of sustained song. Only the low B flats, with their vital pedal effect, failed to project, perhaps through some miscalculation of their carrying power out of doors.

Rostropovich and the orchestra seconded every aspect of Weissenberg's conception, matching his power and equalling his tone. It was a thrilling matter.