Eugene Ormandy began his ninth decade last night with a concert in the Kennedy Center that was marked with youthful vigor. Having celebrated his 80th birthday the day before in Philadelphia, Ormandy led the Philadelphia Orchestra through the Symphony No. 7 by Haydn, then the Oboe Concerto and tone poem, "Also Sprach Zarathustra," by Richard Strauss.

For the Haydn, Ormandy placed his two solo violinists, Norman Carol and William De Pasquale, together with cellist William Stokking in close formation so that their exquisite solos, duets, and trios during the symphony could have the requisite intimacy. At times Carol and Stokking provided a string quarter filled with marvels.

Added to the solo strings were the delights of a flute duet burbling along in the happiest kind of pastoral setting. Haydn may have been more profound later in his life, but he was never more spontaneously joyful.

The Strauss Concerto was written when the composer was over 80 -- yet, like Ormandy, it sounds fresh and vernal. To be sure, there are pages where autumnal reminiscences set in. And that is a good thing, since few composers had as much of their own beauty to remember.

Richard Woodhams, the Philadelphia's new, young first oboe, played the solo lines rapturously and with brilliant technique. The accompaniment, all full of wisps of sound, with quick solo flights from viola, clarinet, and cello, was magical.

Ormandy capped the evening with a broad-gauged reading of "Zarathustra." To hear the Philadelphians' strings in the full cry of the passage about the Backworldsmen is to hear one of the wonders of today's concert world. Fully as impressive was the mysterious opening of the fugue, emerging slowly in perfect sound and contour from the divided lowest strings until it took in the full orchestra.

Ormandy's reading was a long, unbroken line from the majestic opening to the unsolved enigma at the close. The audience shouted its approval.