During a performance of the Brahms first symphony last night, the National Symphony Orchestra worked itself into such a pitch of virtuosity that at the end the audience was cheering even before they could get out of their seats for the standing ovation.

Maybe it wasn't always the most subtle of Brahms playing, but in the huge last movement it was something even more crucial: It was brilliant. This time under Rafael Fru hbeck de Burgos, the National Symphony was sounding like the major ensemble it hopes to show itself to be in the European tour that begins in two weeks.

The extended horn solos near the beginning of the movement soared flawlessly, and the versions of that motive, as they were repeated later in more menacing forms, sounded chilling. Fru hbeck was practicing high-risk interpreting, which is to say it could easily have been a mess, but it wasn't.

For the orchestra the entire evening was a striking success. Before the intermission there was the Beethoven violin concerto with Yehudi Menuhin as soloist. Menuhin has always emphasized the lyricism in the Beethoven and thus taken it quite slowly. But, as much of his bowing and articulation are now in a sad state of deterioration, he must take the Beethoven even more slowly if he is to still bring off those hushed reveries in the first two movements that have been so typical of him (it was about 50 minutes last night). But in the last movement his bowing arm is no longer up to the tricky figures on the lower two strings at any speed.

The program will be repeated tonight, tomorrow and Friday.