On Saturday night at Wolf Trap, Aaron Copland led the National Symphony Orchestra in a bouncy all-Copland evening. On this occasion, the inspiration of Copland the composer, with interpretations of his own works which were livelier, younger and tighter than he has been known to give in the past. He had a firm and friendly grip on the orchestra, and the NSO responded by giving him the best a composer could hope for: exactly what he wanted.

The centerpiece of the concert was the rarely performed "Symphonic Ode," a virtuoso piece for orchestra which, even in this toned-down, revised version, still remains an awsome task. The brass is called upon to produce some very solemn Bronx cheers, the rhythmic articulation of the strings is reduced to a stammer. As with other Copeland pieces, the melodies tend to return with the emparrassing familiarity of a formerly liked high-school friend, and even this bravura NSO performance failed to conceive. still, the closeing pages for brass and violin gave an inexplicably triumphant flavor to the end Ode: an urban Phoenix rising from an ashtray.

In Copland's Concerto for Clarinet and String Orchestra with Harp and Piano, the string section again carried the show, from the beginning waltz through the jazzy rondo finale which was transparent and full of verve.

While Copland's view of the American West is that of a native New Yorker, it has proved hardy, fashionable, and at times very moving. Such as the case with his ballet "Billy The Kid," the SUITE FROM WHICH WAS GIVEN A VERY FRESH READING BY THE (NSO at the close of Saturday's program. Copland's view of Latin America is also that of native New Yorker, but the results have never been as satisfying. His Western post is cute, but his Latino stance is hard to take even when performed very well. One need only listen to any contemporary Latin American Composer, from Chaves and Roldan to Brouwer, to realize the superficiality of Copland's impressions.Copland's "Three Latin American Sketches" came off once more as a budget tour of exotic lands, with the conductor-composer displaying all the insistent rhythmic naivete of a North American tourist taking snapshots while trying to dance the "danzon" for the first time.