"This work is about lies and secrets and about how they influence our lives," says composer Aviram Freiberg of his one-act, fringe opera Ketem (Stain), opening tonight (Friday). Freiberg created it together with his life partner Ronen Moldovan, who wrote the libretto about Yoni, a young man hospitalized after a suicide attempt 10 years ago during army service. The story takes place in the hospital where Yoni is in a coma; his mind is conscious, but no one knows. Freiberg, a horn player with the Haifa Symphony Orchestra, who is also a singer and composer, explains that the piece is suffused with Christian symbolism, as Yoni sacrifices himself to bring salvation to the others, albeit in vain. With homosexual identity as a central theme, the opera is based on a short story by Moldovan, a computer specialist by profession. The sets and the costumes were created at Rakefet Levi School of Design, and young local singers make up the production. Tonight (Friday), 9:30 p.m., at the Rakefet Levi Shool of Design in Tel Aviv, 054-481-8159; Saturday, 9:30 p.m., Hagada Hasmalit, Tel Aviv, (03) 629-2793. More shows are scheduled for December in Tel Aviv and Jerusalem.