Rafael Fruhbeck de Burgos opened his stint as principal guest conductor of the National Symphony Orchestra last night with a program of German romantic music from the 50 middle years of the 19th century.

A gracious reading of Weber's Oberon Overture was momentarily transfigured by Loren Kitt's exquisite clarinet playing. After a beginning that was not quite together, the overture gathered strength and poetic effect.

Yehudi Menuhin was the soloist in the G Minor Violin Concerto of Brunch, for which Fruhbeck found an admirable kind of sinewy strength that is often neglected in the orchestral accompaniment. It was interesting to note Menuhin's obvious approval of the power in the orchestral tuttis.

The great violinist played with total authority, opening up the first section of the work with strength, while in the famous slow movement his tone took on that lucent, piercing beauty of which he sometimes seems to be the sole proprietor. Many in the audience rose to salute him with shouts of approval at the end.

Fruhbeck closed the concert with the Second Symphony of Brahms. With the orchestra in excellent control and offering much lovely sound, the symphony was played with great deliberation. This is a hazardous element in Brahms, whose symphonies are explicitly marked for changes in tempos. While Fruhbeck frequently, and with great subtlety, fashioned broadenings that avoided any hint of seeming to slow down, there were times when ends of phrases threatened to lose the feeling of momentum that is their essence. These were usually followed by speedings-up that did not alter the sense that by a bit too much tampering, a strong forward motion had been lost.