HUANG RUO's STRING quartet A Dust in Time begins simply, with an ascending perfect fourth in the cello, and the quiet reply of a major second in the viola. The violins remain silent as the contrapuntal dialog develops like two voices engaged in prayer. Over the course of 60 minutes, the music increases in complexity and volume, leaving the listener to wonder at times where one voice begins and another ends, before returning to the original back and forth between viola and cello.

The gradual build-up and deconstruction of the music evokes the process of mandala sand painting, where grains of colored sand are poured from thin funnels onto a detailed outline of Buddhist symbols and geometric patterns, only to be swept away upon completion. Tonight at Asia Society Texas Center, the ROCO String Quartet will perform Ruo's complex and sublime composition.

Born in China in 1976, the year that marked the end of the country's Cultural Revolution, Ruo grew up absorbing the three Bs (Bach, Beethoven and Brahms), rock and roll, jazz, and heavy metal. Somewhere in that mix must have been minimalism. But while A Dust in Time certainly draws upon the language of that much maligned style of music and its originators, including Terry Riley and La Monte Young, it presents its own unique challenges for the performing musicians.

"It is a marathon of continuous playing," says ROCO violinist Scott St. John. "It's also a mental challenge, with many long but beautiful cycles of repetition, somewhat akin to driving a lovely desert highway as the sky slowly changes colors. But the player has to stay focused on the road."

In his autobiography Freedom In Exile, the Dali Lama describes the first time he saw a sand mandala. "I almost lost by balance from just looking at it," he writes, "so extraordinarily beautiful did it appear."

So long as Scott and the ROCO String Quartet keep their eyes on the road, listeners tonight will no doubt enjoy a similar epiphany.

ROCO / photo by Ray Kuglar