The crowd of 6,800 that gathered Saturday night at Wolf Trap to hear Itzhak Perlman play Mendelssohn's Violin Concerto with the National Symphony Orchestra was the largest that the facility can accommodate -- and it was a beautiful night for it.

The listeners chose well, because Perlman was at his most resplendent. There is not another concerto that better suits the violinist's capacities. Mendelssohn's meldings of captivating lyricism with the most extraordinary demands for accuracy of pitch and evenness of scale and tone could hardly be better suited to Perlman. And the violinist was at his peak -- relaxed, pensive and assured.

* Mendelssohn has the player darting regularly from the E string to the G string and back again without mercy. Beethoven and Brahms also ask a great deal in this regard in their violin concertos, but the emphasis there is more on intellectual probity. The Mendelssohn focus is more on pure song, and Perlman's mastery of the nuances of melody -- like that of a great singer -- is among the most remarkable of his many qualities.

From his matchless opening note, he set the tone. Everything was considered with great subtlety. The sound was often quite subdued, but always full of tonal body.

Repeatedly, also, there were prodigies of pitch that left one wondering how he did it; no other violinist is more consistently on the mark than Perlman. Further, there was special sensibility to Mendelssohn's harmonic and rhythmic lines; Perlman would stretch and pull, and apply a very wide range of color, but never distort.

All the more remarkable, then, that the event had only one rehearsal, earlier in the day. One of the problems that sometimes mar the National Symphony's summer concerts -- and those of most other orchestras, too, for that matter -- is raggedness from insufficient preparation. But Saturday night in the Mendelssohn, especially, the performers played with real grace, most of all in the winds.

*Conductor Yoel Levi left the orchestral part suitably understated much of the time, a wise course since the violin part is so easily blanketed by the orchestra in the Mendelssohn concerto (even that glorious top note at the last movement's end was clear).

Levi displayed considerable assertiveness, however, in the Mussorgsky-Ravel "Pictures at an Exhibition." The movements were sharply characterized, and the orchestra was in good form.

Mozart's Symphony No. 34, K. 338, was not quite as successful. It was nicely shaped, but the violin sound was a little hard, despite careful dynamic shading.

One problem, perhaps not easily solved: This size crowd gravely overtaxes the roads at Wolf Trap. It was more than an hour before some of the listeners could get out. But maybe that's one of the prices of success.