Star quality is one of the essential ingredients that generates excitement during the summer musical doldrums from the Mostly Mozart concerts here and at Lincoln Center. Normally soloists give this crowd-pleasing dimension, but Saturday night at the season's final Kennedy Center Mostly Mozart event, the star was clearly the conductor, David Zinman.

It was not his only appearance during the week's five programs, but on the other occasion his splendid effort was a bit overshadowed by the superb playing of Mozart by pianist Andre'-Michel Schub. Saturday night, the soloists were perfectly respectable but Zinman was making an extra effort, and it showed, particularly in a bracing performance of Haydn's 95th Symphony that culminated this year's Mostly Mozart week.

Maybe you wonder why one of the most remarkable of Haydn's London symphonies was chosen to end a Mostly Mozart festival; but in light of Saturday's grand performance, there would seem to be no further need for a rationale.

Haydn was Mozart's contemporary, and was quite open in his praise for Mozart as the greater musician. In this symphony, as much as in any of Haydn's 104 (or however you may count them), there is a directness and daring in the way Haydn juxtaposes material of considerable gravity with something else that seems almost casual, which, in its way, surpasses the more introverted Mozart. That is one of the qualities that makes Haydn's music sound Haydnesque.

You could tell from the way Zinman handled the off-beat accent of the opening motif that he was right on top of this quality. There were moments in the slow movement that could have been more precisely pointed, but otherwise Haydn's lusty zest surged forth with spontaneity and delight.

Dylana Jensen, the youngest violinist ever to win the Tchaikovsky Competition, played the relatively unfamiliar First Mozart Concerto in B-Flat. The violin tone was perfectly placed and the interpretation was well done, but a little impersonal. Zinman's accompaniment was strongly characterized.

Pianist Horacio Gutie'rrez played in the Mozart 23rd Concerto. He performed with polish and dexterity, but his sensitivity to the music was not up to the Mozart playing we heard from Schub early in the week. There was a shortage of the metrical purity that is so important to phrasing Mozart; it's not that anything was grossly wayward, it was just that the rein needed for Mozart's expressive framework was insufficiently tight. The sound that Gutie'rrez drew from the instrument was unfailingly lovely.