Kronos Quartet at UCSB’s Campbell Hall

Although several decades of exposure to its recorded music has made the powerful, surging sound of the Kronos Quartet’s approach to the work of American composer Steve Reich familiar, the impact the group makes live can still come as a surprise. The combined effect of these four outstanding musicians — violinists David Harrington and John Sherba, violist Hank Dutt, and cellist Jeffrey Zeigler — along with the amplification that they use in concert and the augmentation of Reich’s scores by a variety of prerecorded elements, ranging from individual human voices to multiple string quartets, takes them far from the standard sound associated with string quartets. And if for the first few minutes it feels as though one has stumbled out of a classical concert and into a postmodern rock show, well, that’s part of their appeal.

Thursday’s all-Reich program began with the 1999 Triple Quartet, and immediately the audience was immersed in the Kronos/Reich world of dense, interlocking chords and drawn-out canon forms. Kronos followed with selections from The Cave (1993), a piece Reich composed as part of a documentary he made with his wife about a historic site in the Holy Land. This piece introduced both the interfaith context in which the rest of the program was intended to be understood and the technique of sound sampling the human voice that would be continued in the new piece WTC 9/11 and in 1988’s Different Trains. While all the music presented on this evening had extraordinary power, it was, paradoxically, the least busy section of all — the “Interior Drone” of The Cave — that perhaps came off as the most captivating, proving that sometimes less is more.