MUSIC REVIEW : Ysaye Quartet Impressive in Laguna : The prize-winning French ensemble proved more than equal to a demanding program of 20th-Century classics.

There seems to be an abundance of good, young string quartets around these days; add yet another: the Ysaye Quartet. The Laguna Chamber Music Society presented this prize-winning French ensemble, founded in 1984 at the Paris Conservatory and now on its first U.S. tour, Thursday night in the Artists’ Theatre at Laguna Beach High School.

The demanding program of 20th-Century classics and Schubert’s A-minor Quartet, D. 804, revealed the group to be remarkably unified and stylistically aware. Its members--violinists Christophe Giovaninetti and Luc-Marie Aguera, violist Michael da Silva and cellist Michel Poulet--seem to think as a unit rather than as individuals, so Thursday’s performances emerged clear in thought and poised in execution.

The group’s performance of Webern’s String Quartet, Opus 28, brought human warmth to what can be an exercise in icy abstraction. The players’ carefully matched tone colors enabled them to connect the widely ranging, disjunct lines into something resembling melodic continuity.

Where Webern’s fragmentation precludes that connectedness, a single expressive arch in the phrasing melded longer stretches of music together. Adding to this overall graciousness were the players’ delicate attacks, even at extremes of range, which asserted that disjointed doesn’t mean ugly.

The quartet had opened with Shostakovich’s String Quartet No. 8 in a cogent and concentrated performance. In the central movements, the players avoided brilliance by opting for sober tempos and heavy bowing. The outer movements unfolded in vast stretches of stillness, leisurely in pace yet never sagging in impulse. Even the long-held notes that underpin much of the activity hovered breathlessly.

As the ensemble came to conclude the piece, a vacuum cleaner somewhere in the building whirred in rude counterpoint.

An all-too-rare performance, lean and propulsive, of Stravinsky’s jagged Concertino for String Quartet rounded out the first half of the program.

To conclude the concert, the Ysaye offered, as it had the night before in its L.A. appearance, Schubert’s A-minor Quartet (reviewed Friday). In this program’s context, the players’ richly colored, coaxing account seemed like a comfortable blanket after the harsh, though welcome, medicine of the first half.