Morlot and Weilerstein memorable at Mann

Composer Hector Berlioz signified many things, but on Thursday at the Mann Center for the Performing Arts, he was the patron saint of young conductors. The artist in question was Ludovic Morlot, the young associate conductor of the Boston Symphony Orchestra who is accumulating prestigious debuts, among them his first outing with the Philadelphia Orchestra.

The Berlioz overture, Le Corsaire, with its long opening string flourishes, seizes your attention dramatically - at least when well played - and assures you that you're not likely to forget the visual image of the conductor making it happen. And yes, it happened.

Morlot is a winning presence, not because of a commanding stature (he's diminutive) or balletic conducting manner. He uses the baton vertically, almost like a bandmaster, though with considerably more sophisticated results. The orchestra was responsive, but whether that was inspiration or professionalism is hard to say: Well beyond Berlioz's ken - as well as that of Tchaikovsky, whose Symphony No. 4 was on the program's second half - is weather interference.

The steady downpour created a layer of sound that wrapped itself around the pizzicato movement of the Tchaikovsky symphony. Some listeners cupped their hands around their ears. That, plus limited rehearsal time in these concerts - and in a symphony that bears the imprint of Christoph Eschenbach's relatively recent interpretation - made Morlot's interpretive profile hard to discern.

The opening fanfare consciously eschewed the more velvety side of the orchestra's brass sound, using this more penetrating timbre to telegraph the profundity of the music's anguish. Morlot definitely knows how to employ rhythm in ways that set off the symphony's progression of musical paragraphs. So he's promising; more than that is hard to say.

No such questions were left by Alisa Weilerstein, soloist in the Saint-Saens Cello Concerto No. 1: The music hasn't a lot of dimension, and Weilerstein's appearance was her third in the last year. Her energy level is the most obvious element of her playing; she's been known to wrestle with her cello as much as play it.

On Thursday, she tempered herself with a level of control that revealed her alluring tone quality as never before here. With her energy focused in all the right ways, this mid-weight work sparkled with meaning, as opposed to cello rhetoric. Always exciting, this time she was extraordinary.