THE SOUL SINGER.

We are living, operatically speaking, in what might be called the Age of the Seconda Donna. During most of the four hundred years since opera originated in the Italian courts at the turn of the sixteenth century, the commanding singers have been prima donnas--sopranos who take on the roles of tragic heroines and, in many cases, make it a point to be as difficult as possible offstage. Attention is still automatically paid to the Violettas, Lucias, Toscas, Brunnhildes, Salomes, and various Leonoras, but recently an intrepid group of women--mezzo-sopranos, who are generally cast in supporting roles, and often as men--have created a brilliant, in many ways more interesting place for the spotlight to fall. Cecilia Bartoli fills concert halls with esoterica by Vivaldi, Gluck, and Salieri. Anne-Sofie von Otter has taken the songs of Grieg, Stenhammar, and Sibelius out of the Nordic mists. Olga Borodina has been the most powerful female voice in the Kirov Opera's resurrection of nineteenth-century Russian epics. Susan Graham has made a brilliant success by exploring recherche corners of the French art song. And in the great, ongoing revival of Baroque operas and oratorios, many of them by Handel, the most luminous presence has been that of the American mezzo-soprano Lorraine Hunt Lieberson.

None of these women have followed a conventional career path, but Hunt Lieberson is the arch-maverick. She has never had a long-term relationship with a recording label, and she has never had a press agent. Most of her opera appearances have been well outside the big arenas, in festivals devoted to close-knit ensemble performances and to innovative staging. (She has sung in only two productions at the Met--John Harbison's "The Great Gatsby," in 1999, and Berlioz's "The Trojans," last season, in which she made a notable success as Dido.) She prefers to work with directors and musicians with whom she is familiar and who share her spirit of adventure--small repertory groups like the Orchestra of Emmanuel Music, in Boston, which is conducted by Craig Smith. Their recording of two sacred Bach cantatas for solo voice and chamber orchestra--"Ich habe genug" ("I have enough") and "Mein Herze schwimmt im Blut" ("My heart swims in blood")--was released by Nonesuch this fall, and it has been widely acclaimed. I first heard Hunt Lieberson twelve years ago with another such group, the New York Festival of Song, at a benefit evening in Leonard Bernstein's apartment, in New York. She sang several Spanish love songs, and when she had finished I went up to her and said, "You have one of the most beautiful voices I've ever heard. Who are you?"

"I'm a violist," she replied, with the trace of a smile.

Lorraine Hunt Lieberson, who was known as Lorraine Hunt until her marriage four years ago to the composer Peter Lieberson, is forty-nine. She did not begin singing in earnest until the relatively late age of twenty-six, and before that she supported herself as a freelance violist. Craig Smith, whom she has known since her student days at the Boston Conservatory, in the early nineteen-eighties, told me that he regards her training on an instrument that has generally played second fiddle to the violin as the key to what makes her so special as a singer. "A viola is a middle voice--it has to be alert to everything around it," he said recently. "There's something viola-like about the rich graininess of her singing, about her ability to sound a tone from nothing--there's no sudden switching on of the voice, no click. And, like most violists, she is also self-effacing: without vanity as a singer. When we first performed the Bach cantatas, she just disappeared as a person."

Two years ago, Hunt Lieberson sang the Bach cantatas in a monodrama staged by the iconoclastic director Peter Sellars, with whom she has collaborated on many projects over the years. For "Ich habe genug," she wore the hospital garb--complete with medical tubes--of a woman who is terminally ill. At one point during "Mein Herze," she was wrapped in a red sash that evoked a remorseful sinner's torment. She dedicated the performances to the memory of her younger sister Alexis, who had died the previous year of cancer. (Shortly before her sister's death, Hunt Lieberson herself had been diagnosed with breast cancer.) Many Bach purists in the audience protested that her voice alone would have been sufficient to serve the music and its theme of redemption through suffering. Others found the performances almost unbearably moving, as much for the beauty of the singing as for the intense conviction with which she conveyed the agony of suffering and, eventually, the ecstasy of spiritual release.

Hunt Lieberson told me that for her the staging and the singing were "inseparable," and on the recording she seems almost ...