Once in a while, a guest conductor comes to the National Symphony and shows Washington a kind of orchestra that we seldom see in the week-to-week routine of concert-going. It happened several years ago with Claudio Abbado, and those who heard his program of Mahler and Richard Strauss are still impatient for the day when his schedule will allow a return visit. It happened so regularly with Rafael Fruhbeck de Burgos that he was finally appointed principal guest conductor amid general applause--including the applause of the most critical audience in town, the members of the orchestra.

Last weekend, it happened with Klaus Tennstedt under circumstances that hardly seemed promising: the opening of a Beethoven festival that required the orchestra to play two completely different programs on successive evenings. Even when the material is familiar to the orchestra (as it must be in a Beethoven festival), there is usually a hit-or-miss quality in the playing for such a musically crowded occasion; an orchestra can produce only limited results in a limited time. But on Saturday night, under Tennstedt's baton, the National Symphony performed the "Egmont" Overture, the Violin Concerto and the Fifth Symphony with a polish, a balance, and an assured interpretive authority that clearly earned a standing ovation from a capacity audience. There was a freshness in the playing that made these thrice-familiar works seem brand new, a joy in the music that made one want to hear more -- much more -- of the NSO-Tennstedt combination.

The evening was not completely free of contretemps. In the first movement of the Violin Concerto, soloist Mark Kaplan seemed to take a while to warm up, even though he got a running start by playing a few bars as part of the orchestra's violin section before making his first entry -- a luxury unavailable to the soloists for the five piano concertos. There seemed to be some stylistic disagreements at the beginning, with the conductor in a dramatic mood while the soloist was feeling more lyrical, but unanimity was established by the time Kaplan reached the cadenza (the magnificent Kreisler cadenza), and there were no problems for the rest of the performance. Actually, the cadenza and the conclusion of the first movement were a foretaste of the slow movement, which was played exquisitely by both the soloist and the orchestra. Here as in many other passages during the evening, Tennstedt drew a rich pianissimo sound from the strings that is not heard nearly often enough in NSO concerts.

Control of the strings, and particularly of the violins, was one of the keynotes of the evening. It seemed to be the principal ingredient in the special transparency of sound that Tennstedt produced, and it allowed the woodwinds and the brass to be heard with unusual clarity and in unusually good form. Watching the conductor's sweeping and very angular gestures, one might have expected rather eccentric interpretations, but the music that emerged from his contortions was beautifully poised and solidly in the Central European mainstream of interpretation.

This Central European element is what is most notably missing among the flavors steadily available these days from the National Symphony Orchestra. Washington already enjoys frequent performances by distinguished Russian and Spanish conductors to whom Germanic music is a sort of second language, though one in which they are sometimes very eloquent. For a better balance of programming, it would be good to hear more from this great German conductor. May he return soon -- perhaps with some Mozart in his portfolio.