Tan Dun's "Ghost Opera," heard Monday night at the Freer Gallery, is a rarity: a hopelessly postmodern hodgepodge that works on its own terms. It's a melange of musical styles, novel sound effects, shouts and screeches, East-meets-West cultural clashes and beautiful sounds that are there only because they're beautiful or beautifully exotic or beautifully evocative.

The subtitle reads "for string quartet and pipa with water, stone, paper and metal." Thus Cho-Liang Lin (leader of the Gotham Musik ensemble)--before he picks up his violin--is first heard gently spashing water in a large bowl as a musical effect. Later, other members of the group--violinist Michael Shih and violist Ori Kam--clink small stones and then metal bowls together. Near the end, pipa player Min Xiao-Fen rustles a paper sheet that's so long that it traverses the entire stage. It sounds like distant thunder.

Cellist Kristina Reiko Cooper plays, and shrieks, from behind a sheer white screen. The musicians move now and again to different stations around the stage; the violist even starts at the back of the auditorium. Yet "Ghost Opera" is never burdened by a studied hipness or lack of identity, and there was a compelling earnestness to the way Gotham Musik performed it. When future cultural historians refer to the High Postmodern era, they'll surely cite "Ghost Opera," written in 1994, as a classic.

Min opened the evening with Tan's "C-A-G-E III" (1997), an improvised homage to John Cage for solo pipa. As the title indicates, the late composer's name is spelled out with plucked musical notes on the lutelike instrument. Min added lovely phrases, shimmering and oddly pastoral; for the closing section, she made rapid trills (an effect also used in "Ghost Opera") sound like water dripping onto bamboo.

Between the Tan works was Shostakovich's String Quartet No. 8, Op. 110, in a fiery but sorely unbalanced reading. Lin, a formidable concert violinist, is temperamentally more attuned to the role of grand soloist with orchestra than team-playing chamber musician. He drove the music with intensity but, for tonal heft, swallowed his colleagues whole.