It was pitch black at the Terrace Theater last night when the darkness was broken by a woman's face, and the American premiere of Heinz Holliger's opera "Not I" was on its way.The voice grew from the live soprano to its electronic mirror, taking over with different visions of the same rality and amplifying Samuel Beckett's austere text 16-fold with a sense of musical and dramatic wonder.

If Beckett's world seldom boasts of clear bounderies, Holliger's musical treatment illuminated its space. As the nameless woman's voice was multiplied electronically, she became a presence to her own sounds, a witness to her identity. She defined herself unwillingly, "raving away at it all, trying to make sense of it," while her very being soon escaped the confines of definition. What the apolitical side of existentialism has left behind, Beckett approached and Holliger achieved with "Not I."

The score, for soprano and tape, contains much that could have come from Berio or Strockhausen, with melancholy melodies that recall Penderecki's early works. As a matter of fact, there is nothing strikingly new in the piece, except for its uncontainable humanism, that feeling that no matter how mistreated, amplified or objectified the human voice may be, it remains human. Much of this was attributable to Phyllis Bryn-Julson, the formidable American soprano for whom "Not I" was composed.

Whether heard live or in its several transformations, whether laughing, crying, sighing or simply vocalizing, Bryn-Julson's voice was a sensuous miracle. It is she whose feminine presence kept the music from becoming abstract, she who never let the audience forget that this ageless, nameless voice belongs to one of us. Her dramatic singing turns a potentially alienating score into a plea for human values, and her performance is unforgettable.

Indeed, it would have been far better to let her face and voice reign over the small stage rather than to show the accompanying film by director James Herbert. Often in new works the multimedia effects are not on the same level as the music, and this production was no exception. Herbert's film would have been called experimental in '60s, with its intermittent cross-cutting and pseudo-Freudianisms. Frankly, it might have been more commanding on a much larger screen; as it was, the effect was like seeing a minor Rothko painting at too long a distance.

Janacek's too seldom heard "Diary of One Who Vanished" followed, giving us a chance to hear the rich mezzo of Rose Taylor as the Gypsy. The entire program will be repeated tonight at 8:30.