Angela Denoke has been here before. The acclaimed soprano's previous trip came during a pivotal period in her studies at the Hamburg Music Academy, and she still fondly remembers getting to sing in Jerusalem in a production of Beethoven's "Missa Solemnis." Now she's back to sing Arnold Schoenberg's four-scene musical monodrama "Erwartung" ("Expectation"), which she'll perform Monday in the penultimate evening of the Jerusalem International Chamber Music Festival at the YMCA Concert Hall. The sole female vocalist to perform at this year's festival, Denoke is already quite familiar with the piece, having first performed it under the baton of Daniel Barenboim in Berlin and Vienna this spring. She repeated the role in June at the Covent Garden Opera in London, where she garnered ecstatic reviews. Composed in only 17 days back in 1909, "Erwartung" was Schoenberg's first major atonal work. It tells the story of a disturbed woman who spends a night alone in the forest searching for her lover. Schoenberg described the piece when he wrote it as "a representation of the most terrifying psychological stress a human being can experience compressed into a single second, with everything that happens in that second detailed in slow motion." "This half-hour opera is musically and dramatically very intense," Denoke wrote in an e-mail before arriving in Israel. "Schoenberg takes a few seconds of this woman's quickly changing thoughts and stretches them over the half-hour. It is an extremely difficult task for the singer to show the audience this rapidly changing thought process, this incredible tangle of emotion and feeling. "To portray this woman with all these levels of emotion, some of which I know and some of which I don't know personally, is exactly what fascinates me about this opera. [It's] the story of a woman driven by love and jealousy in which we are forced to decide between what is real and what is the product of her wild imagination." Denoke performed at the chamber festival for the first time Saturday evening, singing Schoenberg's "Brettl Lieder" cabaret songs and Shostakovich's "Seven Romances on Poems by Alexander Blok." The German songstress was born in Stade, a small town near Hamburg. She's the only professional musician in her family, but says the rest of the Denokes "love music and love making music by either singing or playing an instrument." Her first formal exposure to music came in the form of piano lessons, but the instructor recognized her vocal talents and suggested she focus on singing. It was around the time of her "Missa Solemnis" performance in Jerusalem that Denoke committed herself to music as a professional option, changing her major to vocal studies. Her first solo role, she recalls, was as the Second Lady in a 1989 production of Mozart's "The Magic Flute." A year later, she sang the part of the Countess in "The Marriage of Figaro." She graduated in 1992 and joined the Ulm Theater as a soloist. She was recruited four years later by the Stuttgart Opera, and her international career was launched. She has by now sung at most of the world's major opera houses, including those in Berlin and Vienna and at the Metropolitan Opera in New York. In 1999, German magazine Opernwelt named her its Singer of the Year. Most opera singers learn a fair number of roles, but Denoke has mastered more than most - 25 at last count. She learned a lot of them, she says, during her start at the Ulm. "Being a member of an ensemble means you must learn a variety of roles," she said, "and because I am a quick study and love learning new music, I naturally amassed more of them in those early years than most singers." Her favorite performances came as Sieglinde in Wagner's "Die Walk re" and as the Marschallin in Strauss' "Rosenkavalier," her Met debut. She's also recorded the part of Marie in Berg's "Wozzeck." She says she's still looking for challenges, and that she would never take a role just because it suits her voice. It also has to be musically interesting. "In the very best instances," she said, "all of these things come together: the musical work, a good director, good colleagues - and a good feeling from the public."