The National Symphony Orchestra scored the greatest triumph of its European tour so far with tonight's concert in Vienna's illustrious Musikvereinsaal.

Perhaps it was because of the hall, generally agreed to be the greatest of all the world's concert halls. It is a room hallowed by memories of Brahms, Bruckner, Mahler, Strauss and other great composers, conductors, and soloists of the past century who have performed there.

The orchestra's success may also have been helped by the rapt attention of one of the world's most critical audiences.

For whatever reasons, the orchestra played at its finest tonight. Mstislav Rostropovich brought the "Lohengrin" preludes to a peak of sustained beauty he had not previously achieved. Did the Wagner preludes reach special heights because the music hall is only a few short blocks from the Imperial Hotel? That is where Wagner and his family stayed for a month in 1845 while both "Lohengrin" and "Tannha user" were being prepared for the Vienna Opera.

Rostropovich then proceeded to Schubert's Third Symphony, which brought Schubert home to the native city where his symphonies were never played in his lifetime. And again the performance was the finest Rostropovich has yet produced on the week-old tour.

When Rostropovich reached the Tchaikovsky Pathe'tique, it was clear that this performance, like the one in Mannheim last Wednesday, was going to be very special. The sound of the orchestra took on the golden tone that comes only in Vienna's great hall. The playing was solid, the brass at its most brilliant, and the strings and winds seemed inspired by the particular luster of the place. As in West Berlin last Monday, the National Symphony sounded as it never can sound in Washington.

It was also interesting to note that in Vienna, as in Mannheim, the audience interrupted the symphony with applause after the third movement even though Rostropovich indicated he wanted to move directly into the finale.

There have been differences in audiences and in halls from city to city. But in nearly all the places where the National Symphony has played, the orchestras have been seated on risers. This is so desirable, both musically and from the standpoint of the audience's ability to see as well as hear what is going on, that it should be made a permanent feature of concerts in the Kennedy Center.

After the Tchaikovsky, most of the audience remained in place, cheering until it had been given three encores, increasing its frenzied approval after each one. The violin section never sounded better in the "Perpetual Motion" of Paga- nini, and Loren Kitt scored the same great fete in George Gersh- win's Promenade that he does each time it is included among the encores.

The Vienna program will be repeated Monday night in response to the great demand for tickets, and the house is sold out as it was for tonight's performance. Then the orchestra goes on to Amsterdam, Paris, London and the rest of the tour.