If “SAGA of the 21st Century Girl” is the rock opera thriller it claims to be, then rock pioneer Chuck Berry, 87, is about to roll into his grave ahead of schedule. Written and composed by Sheli Nan, known for decades of work in early music, “SAGA” made its world premiere over the weekend at the exceedingly dry and musically unfriendly Osher Studio in Berkeley. Onstage are five unamplified opera singers, an extremely quiet orchestra of violin, alto flute and clarinet, plus two of the quietest electric instruments you’ve ever heard: piano and bass. While rock operas may still be an in-thing these days, there is nothing remotely rock about an attractive, melodically repetitive and sparsely orchestrated score, dutifully conducted by Mary Chun, whose volume never once exceeds the polite. Although it certainly has its share of sex and violence – it even has a mad scene of sorts – this 75-minute work has a far too familiar story line. In a nutshell, “The Girl” (Crystal Philippi), who is contemplating suicide, flashes back to her youth with a totally self-absorbed, pill-popping alcoholic Mother (Valentina Osinski) and equally boozed up Father (Jo Vincent Parks). Both consistently ignore her cries for love. As The Girl matures into the age of 4G pseudo-connectivity, the story moves forward to her disastrous time with her blind internet hook-up of a dirty old man (John Duykers, who doubles as the male Shadow). Along the way, there is ample commentary from a shadow Greek chorus of sorts (Duykers and Alexis Lane Jensen), whose work with a mirror is but one of director-designer Melissa Weaver and choreographer Philippi’s many insightful touches. The Girl’s final period of bipolar lunacy, gently augmented by Matthew E. Jones’ attractive but tame video projections, invokes elements of “Carrie: The Musical.” Wanting, however, are the camp elements that are that musical’s saving grace. “SAGA’s” salvation of sorts lies in the quality of the performances. Duykers, who premiered the role of Mao Tse-Tung in John Adams’ “Nixon in China,” may be approaching his sixth decade performing, but his standout voice remains a steady and expressive marvel. Equally intact is his wit, communicated by facial gestures and body language that provide a welcome antidote to the predictable libretto. Philippi is uncommonly strong as she successfully navigates from teddy bear-hugging innocence to hip gyrating femme fatale, virtually lighting up the stage before her black acts commence. Osinski is her adult mirror of sorts, and equally compelling. There isn’t a weak link in the cast. But if this is a thriller, it must require some very arcane drugs to fully appreciate.