Out in Potomac, there is a soprano named Sutherland who has sung to packed houses in Europe and turned down offers from La Scala, the Paris Opera and the Met. Instead, she sings with the Theater Chamber Players in the Kennedy Center's tiny Terrace Theate, which still has some empty seats for tonight's performance.

Phyllis Bryn-Julson, wife of organist Donald Sutherland, does not use her husband's name professionally; another soprano with that name hit the limelight before Bryn-Julson made her formal debut with the Boston Symphony 15 years ago. Instead, she has given international acclaim to the hyphenated Norwegian name with which she was born 36 years ago in Bowden, N.D. She has done it the hard way -- not by performing the standard classics that everyone loves (or at least respects), but by taking risks, attaching her name to new compositions that are hard to sing and sometimes die unlamented after the first performance.

That doesn't seem to be the destiny awaiting the newest item in her repertoire: a mini-drama for soprano, soundtrack and movie projection called "Not I," composed for Bryn-Julson by Heinz Holliger with a text by Samuel Beckett, which had its American premiere last night. (It is reviewed on page C11.) After its world premiere at Avignon last year, "Not I" had more than a dozen sold-out performances in France and evoked a string of critical superlatives. To Le Monde, Bryn-Julson's singing was "lumineuse"; to Le Figaro, "extraordinaire" and "merveilleuse"; to Le Nouvel Observateu, "prodigieuse"; and to Le Quotidien, "exceptionelle." One critic found her voice "beautiful, supple, rich-textured," while another thought it was "a miracle of ease and naturalness in its acrobatics, a soft, warm presence that is unknown in contemporary music."

Bryn-Julson doesn't think it was necessarily her voice that sold all the tickets. Composer Holliger, already internationally famous as the world's leading oboist, has been building a solid reputation as an avant-garde composer, and Beckett's credentials as a writer are eqully impressive. "This is a piece that was sold out in Europe when it was announced that it was going to be written," she says. "There just simply weren't seats available, both in Avignon and in Paris. I have many American friends who would appear at the door. This happens when I sing over there; they come and try to get in, and there's nothing to do. I can't put them in my dressing room, where they'd miss the whole thing. It was a shock. I've seen packed houses before, but not for something this far-out."

Why don't American audiences flock to new music the way Europeans do? Bryn-Julson thinks it may be a question of insecurity: "People know the works of the old composers. They get concerned if they don't understand the piece; they think they should have a grip and an immediate understanding of what's happening rather than allow it to happen and come back and maybe listen to it another time."

Insecurity has never been a problem for Phyllis Bryn-Julson, even when she had to tell her family that she was going to dedicate her life to the risky business of contemporary music. "They did sort of balk," she recalls. "My mother was concerned.I think everyone is concerned about people going into music, because you just don't make a fortune at it unless you have tons of money to put into publicity. But I never thought twice about it. I new I would get my education, and I knew I could work as a waitress if all else failed; I could work pumping gas. There is a job out there if one goes after it . . . I don't waste time with people -- students or other people -- who have closed themselves up, who make a nice little tunnel for themselves and travel through life. I guess that's security, and I suppose people who are suffering from insecurity should stay in that little tunnel."

Bryn-Julson's life has become anything but a tunnel. She did not begin as a singer but as a piano student at Concordia College in Moorehead, Minn. aWhile she was there, Gunther Schuller first noticed the ease with which she sight-read 12-tone music and then was impressed by her voice, a voice of unusually pure tone and perfect pitch -- even in quarter tones -- over a three-octave range. She married right after college and has two children: David, who is almost 12, and Karen, who is 8.Besides her singing, she teaches at the University of Maryland, and her specialty in contemporary music has broadened to include the classical repertoire -- particularly in the United States, where the audience for contemporary music is still small

"I love it all, old music and new," she says. "You know, there are some pieces that have to be weathered, and I perform a lot of new music that isn't going to survive -- I have to admit it. But that doesn't mean it shouldn't have a chance. And that has happened forever -- since way back, music was tried and tested and thrown away. And there is a lot of old music that should have last performances; it's not just the modern things that should have last performances. Once in a while, it's worth it when a gem comes along -- like the Del Tredici 'in Memory of a Summer Day.' I went to St. Louis and learned that thing and performed it and it was a bear to sing. It was tough. Right after that, I went to Europe and sang the Del Tredici 'Adventures Underground' with the Concertgebouw, and by the time I got home this piece in St. Louis had won the Pulitzer Prize. If that happens to me once in my lifetime, that's a lucky feeling; it's a wonderful feeling."

Although it is often difficult to sing, she finds contemporary music good for her voice: "I feel that having sung something like Mozart, Verdi, Mahler or whatever, the opportunity to sing something contemporary that has tremendous leaps really puts my voice back into good condition, because it has to be flexible to do those things. And if the flexibility isn't there in the contemporary things, then I'm in trouble vocally, I have already tension creeping in. So for me, the combination of the two is really healthy and sometimes saves my life -- literally -- when I've sung too many Verdis or Mozarts or Bachs or whatever."

Her commitment to contemporary music and to her family has kept her from doing more work in staged opera, it would simply take away too much time that she already has pledged elsewhere. "It doesn't feel good to say no to people like these," she says, referring to La Scala, the Paris Opera and the Metropolitan. "It would have been fun, and what a growing experience. But I feel that I can do my things at home . . . I should be working here and not have to spend three months away from home."