Cellist Alisa Weilerstein, a captivating and technically brilliant performer, embodied romantic ideals in her concert Friday night with the Honolulu Symphony and guest conductor Emil de Cou.

The encore was particularly emblematic, her performance of the famous Bourée being not so much by Bach as a variation on Bach. It was "romanticized," that is, heartfelt, cadenzalike, and idiosyncratic, with wide fluctuations in beat.

In Dvorak's Cello Concerto, Weilerstein's entrance did not rise out of the orchestra's long introduction but erupted in a passionate, almost violent outburst. Every note of the concerto became high drama, and even the folklike song theme was laden with vibrato.

In short, the drama of Weilerstein's performance out-dramatized Dvorak's music, and the focus remained firmly on her.

As her profile noted, "passionate musicianship" is Weilerstein's forte.

Not surprisingly, solo passages, such as the cadenza in the second movement, displayed Weilerstein's exemplary musicianship most fully, and the exuberant third movement suited her gypsy fire best. The most exquisite moment, however, was her subdued but quietly shimmering close.

Maestro de Cou, a talented, up-and-coming young conductor currently with the National Symphony Orchestra, led the Honolulu Symphony with style and energy. Tall and lean, he moved gracefully, a joy to watch.

Although also young in age, de Cou is a "young conductor" primarily because of his interpretations and the sound he elicited from the orchestra. De Cou clearly hears with discrimination, has studied the music, and has the skills to lead.

On Friday night, he revealed a flair for shaping and defining phrases, but the larger issues of balance and ensemble suffered: the pizzicati at the opening of Brahms's second movement, for example, or the violins' accompaniment in the fourth, overshadowed their melodies. Although de Cou creates the kind of clarity that made von Karajan famous, it was not always apparent that he had decided moment-to-moment exactly which of the lines was primary and which secondary or tertiary. Tempi were also often on the fast side, undermining the music's depth, another trait that runs with youth. De Cou opened the concert with an exuberant, exciting performance of Dvorak's Carnival Overture, the middle of a three-piece set about nature, life and love. He saved his favorite, Brahms's monumental Symphony No. 4, for last, and conducted the piece with obvious pleasure. In response, the orchestra delivered several outstanding solos, most notably those by clarinetist Scott Anderson and flutist Susan McGinn.

De Cou's reading of Brahms was surprisingly unconflicted, as though the piece were "nice" or perhaps too great to need "interpreting": The music flowed smoothly over wrenching dissonances and softened emotional upheavals.