Even if Ute Lemper weren't a dazzling vocal technician, a powerful and erotic dancer, and an imaginative and chameleonic actor, the sheer range of her repertoire would set her apart from every other singer working in cabaret, musical theater, and pop. On past recordings she has radically reinterpreted material by European giants like Kurt Weill and Friedrich Hollaender and contemporary British and American rock artists like Elvis Costello and Tom Waits. Her versatility has made her seem almost schizoid on occasion, and her appropriation of vocal hallmarks associated with singers as varied as Marlene Dietrich, Billie Holiday, Eartha Kitt, and Annie Lennox has sometimes made her sound mannered. But her new Decca CD, But One Day..., affirms that her artistic identity, though multifaceted and eccentric, is consistent. Selections by Weill (a sensuously jazzy "Speak Low"), Parisian cabaret god Jacques Brel (a softly intense "Ne me quitte pas"), tango composer Astor Piazzolla ("Buenos Aires"), and the team of Hanns Eisler and Bertolt Brecht ("Ballad of Marie Sanders, the Jew's Whore," written in protest of the Nazi race laws) are juxtaposed with new songs by Lemper herself in a blend of expressionist art-song and pop idioms. In each piece she focuses on rebellious, passionate, even obsessive emotional states, yet, in the manner of her idol Brecht, distances herself and her audience so that they may dissect these extreme manifestations of human behavior. This strategy of detachment is abundantly clear in her live performances, in which every number is a miniature drama enacted with highly stylized gesture and movement. Her Chicago performance this weekend is presented by Performing Arts Chicago, which has also engaged her for a pricey gala on Monday, April 14, honoring architect Helmut Jahn. Sunday, April 13, 7 PM, Athenaeum Theatre, 2936 N. Southport; 773-722-5463 or 312-902-1500.