Any schmuck can toss off a few words of Yiddish (Al D'Amato, are you listening?) but it takes a 2-decades-old company like A Traveling Jewish Theater to mine the true beauty of the language. ATJT's premiere of Diamonds in the Dark: An Exploration of Yiddish Poetry does this by framing Yiddish and English words theatrically, using music and movement. Yiddish, an amalgam of German, Hebrew, and Romance languages, is spoken by millions of people worldwide, from France to Mexico, and from that rich and widely varied base the company has compiled a selection of 20th-century poems that reflect a particularly tumultuous time for Yiddish speakers. A Jewish gangster's funeral in the '20s and a modern Jewish woman's struggle over sexual and cultural identity are among the experiences these poems describe; the poets themselves include early American immigrant Jacob Glatshteyn (one of the first writers of Yiddish free verse), H. Leivick (who was exiled to Siberia for his anti-czarist activities), and Irena Klepfisz (author of Dreams of an Insomniac and the rare modern American writer to incorporate Yiddish into English-language poems). ATJT founding member Albert Greenberg steeps the musicality of the language in a jazzy postmodern score, and contemporary choreographer/collaborator Stephen Pelton sets the piece in motion. Diamonds, the first in the company's new theater, previews Thursday at 8 p.m. (and runs through Dec. 27) at A Traveling Jewish Theater, 470 Florida (at Mariposa), S.F. Admission is $20-25; call 399-1809.