SOMERVILLE -- ''Sleeping or dreaming, the dreamer must accept his dreams." So says Death, in the guise of a beautiful black-haired princess, to Orpheus, a French poet, in Jean Cocteau's film ''Orpheus." It could stand just as well for the spirit in which the film should be watched. Cocteau's witty and casually surreal fable hangs only loosely on the Orpheus myth, which seemed to interest him less for its plot or moral than for the portals it opened between the worlds of the living and the dead. Better to luxuriate in its visual dreamscape than to ask what the dream means.
That was the spirit in which the conductor Jane Ring Frank and her excellent chorus, the Boston Secession, offered their live rescoring of ''Orpheus" on Friday night. The soundtrack devised by Frank and musical adviser Robert Fink seemed designed to intensify the film's playful mystery rather than unlock it. Call it high-concept mood music. When Orpheus watched the Princess walk through a mirror to the netherworld, the chorus sang the austere dissonances of Arvo Part's ''Solfeggio." Attempts to decipher otherworldly messages over a car radio were accompanied by an excerpt from Philip Glass's ''Einstein on the Beach."
For the most part, the chorus and a small guest ensemble did extremely well by this ambitious project, their sixth such undertaking. There was a sense, though, that a few details had yet to be ironed out. The film's dialogue was brought in and out at odd times, and balances, understandably, sometimes favored the movie, making it difficult to hear the nuance that Frank and her wonderful singers brought to the music.
At its best, the live score allowed you to slip unquestioningly into the film's sleek ambience. Still, you couldn't help hunting for the meaning behind some of the musical selections. The opening scene's brawl at the Poet's Cafe was set to a jaunty chorus from Monteverdi's ''Orfeo." Orpheus's first encounter with the Princess, heavy with portent, happened to the equally jolly strains of ''All We Like Sheep" from Handel's ''Messiah." Was the music trying to tell a different story behind the film's back? What did it all mean?
''You try too hard to understand," the Princess tells a bewildered Orpheus. ''That is a mistake."