To listen to Rostropovich conduct a standard work like the Brahms Fourth Symphony is a spur to study every marking in the score anew. During the past week, with the handsome new sound of the enlarged orchestra serving Brahms more elegantly than any NSO has been able to in the past, it was fascinating to note where and how Rostropovich scrupulously followed Brahms' directions, where he added some of his own, and then to wonder the perennial "why?"

In general, Rostropovich took a broadly romantic approach to the work, more in the vein of Bruno Walter than Toscanini. There were times, as in the third movement, when the vigor of his pacing and accent reminded me strongly of Koussevitsky in the same music.

Brahms unmistakably marks ritards in this symphony. Are they the only ones he wants? The first of them occurs 10 measures before the end of the second movement, followed at once by an "a tempo," and immediately again by a second, "little" ritard. These Rostropovich took beautifully, with poetic effect.

But he placed two big ones in the first movement: the first at letter "K," where Brahms writes "dolce." But recently, in reading violinist William Primrose's autobiography, I found that one of his colleagues once remarked to him that nearly always when Brahms says "dolce" he also wants a ritard. Hmm-m-m. Rostropovich handled the ritard at "K" very well, although it might have been more effective had it been slightly less slow.

The other unwritten ritard in the first movement came at the very end. None is written; one is customary. Again, it might well have been somewhat less. In a way, Rostropovich seemed to prove this by the superb manner in which he drove to the end of the scherzo with no hint of a let-up, and repeated almost the same thing at the very end.

Approaching the famous flute solo in the finale, he broadened the tempo, as if to set the stage for the new solo flute, Toshio Kohno. She shone beautifully in the spotlight thus provided.

In considering Rostropovich's ritards, it would be a good idea to remember that European tempos, as George Szell enphasized some years ago in an interview, are always broader - that is to say slower - than in this country. Is a ritard right in Europe but wrong in this country?