Mstislav Rostropovich opened and closed the first concert of the National Symphony Orchestra's 51st season last night in the most festive of keys, C Major.

Following "The Star-Spangled Banner," Rostropovich launched a properly brilliant reading of the Symphony No. 48 by Haydn, the one called "Maria Theresia." Part of the brilliance came from the use of optional trumpets.

The orchestra, in top form all evening, offered crisp playing in the outer movements, turned songful in the slow movement, and served up the right kind of accents in the minuet.

Stravinsky's "Symphony of Psalms" divided Haydn from Saint-Sae ns. This is not only the Stravinsky centennial, but also the 50th anniversary of the first performance of the work, which was commissioned by the Boston Symphony for its own 50th anniversary.

With Norman Scribner's Choral Arts Society singing magnificently, Rostropovich conducted an eloquent account of the famous work. With 10 cellos gathered in a semicircle in front of him -- there are neither violins nor violas in the score -- Rostropovich moved the vast sounds of the wind and singing choirs between the intimate moments that mark this music as some of Stravinsky's greatest, and the glorious, large moments that suggest celestial visions.

The famous opening cadence of the final Psalm 150 had precisely the right luminous quality, a texture which today is heard as a prefiguring of Olivier Messiaen. It is a shame the program did not provide the texts of the three psalms. Few of us carry them in our heads.

The finale came in the Third Symphony by Saint-Sae ns, the one known unfairly as the "Organ Symphony." The injustice of the label stems from the fact that the two pianists called for in the score have a far more difficult assignment than the organist, whose task is quite easy. The dazzling pianists were Hugh Wolff and Lambert Orkis.

Much of the effect of the first part of the symphony depends on the quality of sound produced by the violins, and the National Symphony violins sounded beautiful. So did the whole orchestra as it moved into the heart of the work. Rostropovich took a broad view of the music, leading both strings and winds at a virtuoso pace in the presto passages. For greater contrast and a more impressive impact, the adagio (which, to be sure, is marked poco adagio -- a "little adagio") should be taken far more slowly. It should give its hearers the sense of infinite peace. Rostropovich increased the tempo in ways that denied the music its finest effect.

But for his conducting of the entire closing section, Rostropovich is entitled to waving flags and shouting crowds. The whole thing ended in a glorious conflagration. Anthony Newman was the organist. Most of the time the organ registration was a crucial touch cool. In the exciting dialogue between the organ and the full orchestra it was nearly inaudible. Perhaps someone should check out in the hall for balance. The organ needs to be far more in the foreground. The concert will be repeated tomorrow, Friday and Sunday.