You can tell an opera singer by her voice. Grace Bumbry's echoes down the phone lines from her home in Salzburg with a rich, honeyed lilt. Born in St. Louis, raised singing in her church choir, now living in Austria after decades in Switzerland, Bumbry has a warm speaking voice colored as much by the music she has sung as by her upbringing. There's a hint of an Italian sunniness to her vowels and the lightly rolled R's; an echo of German lieder in the crisp cutoffs of consonants, the precise diction. 'One really can't take me as an example,' she says. What she means is that young singers today can't hope to burst onto the scene at 23, as she did, with a voice that matured early thanks to the intensity of her singing in her high school years. But she could also be talking about the versatility of a vocal range that carried her from mezzo-soprano to soprano roles and back again. Or the brilliant career, one of the most notable of the late 20th century. Bumbry has been singing in Europe since her debut in Paris in 1960, at age 23. 'Back in those days, you felt as if you were being given a lesson,' she says of the all-important exposure to European cultures as a young American who first went over to immerse herself in the German and French repertory. The next year, she gained international attention and acclaim as the 'Black Venus' in Wieland Wagner's Bayreuth production of 'Tannhauser' -- the first African-American singer at Bayreuth, in a role that is meant to be the epitome of female beauty. Some protested. More, though, raved. 'I was actually motionless on my throne,' she recalls now of the role. Wieland Wagner (the composer's grandson, who revolutionized Wagnerian stage direction with his minimal, deeply thoughtful productions, and who defended Bumbry by saying, 'My grandfather wrote for vocal color, not skin color') 'wanted facial expressions and he wanted the sound to come from inside, not just some lovely movement onstage.' She remained enthroned for the next four decades -- as one of the leading singers of her time. In her prime, Bumbry was the epitome of the glamorous American opera singer, driving an orange Lamborghini and married to a Swiss tenor who devoted himself to her career. It was a long way from St. Louis, where she grew up in a middle-class home, the child of a railroad freight handler and a homemaker whose family all sang in the church choir. Bumbry studied music intensely even at Charles Sumner High School, the first all-black high school west of the Mississippi, and won a local radio competition at the age of 17 singing 'O don fatale' from Verdi's 'Don Carlo.' Part of the prize was admission to a local conservatory, but that proved impossible; the conservatory was unwilling to take a black student. Bumbry ended up studying first at Boston University and then at Northwestern, where she met the great soprano Lotte Lehmann, whom she has credited as a second mother. 'Lehmann did not teach voice,' she said. 'She taught interpretation of opera and lieder' -- one reason Bumbry focused on the recital literature, as well as opera roles, throughout her career. Lehmann sent Bumbry to another teacher, Armand Tokatyan, who believed 'in using your whole voice, not limiting yourself to any specific category,' she says. Bumbry started her career as a mezzo-soprano, beginning with Amneris in Verdi's 'Aida' at the Paris Opera. But, she says, the director of the Paris Opera, A.M. Julien, had actually offered her the soprano role of Aida; in what she calls 'a very important moment,' she opted for the mezzo role of Amneris instead. Her self-assurance, and her choice, seemed to be borne out by an almost immediate rise to the top. Within the next few years she had sung Carmen, Eboli (in Verdi's 'Don Carlo'), Amneris and other major mezzo roles at Covent Garden, La Scala, Vienna and the Metropolitan Opera. Her first professional performance in the States took place after a state dinner at the Kennedy White House. Yet for all of the bronze darkness of her voice, it also rose to a gleaming top. She was performing soprano roles even during her early years as a member of the ensemble in Basel, Switzerland. By the 1970s, she had made the transition to soprano altogether, expanding her range to Aida as well as Amneris, to Puccini's Tosca, to Strauss' Salome, or to Verdi's dark anti-heroine Lady Macbeth. (Her first Tosca, at the Met in 1971, took place under a conductor who was making his Met debut: James Levine.) Many listeners had trouble accepting her change of register. 'People took offense after I, quote-unquote, changed vocal categories,' she says now. Why, she doesn't know. 'I have been trying to figure it out. It had to do with familiarity; they were accustomed to hearing me in that repertory. ... The first four or five years, there was consternation in many courts.' Critics, then and now, zero in on her slightly paler notes at the very top of her register as a reason to bemoan her choice. But, Bumbry says, 'it didn't change my popularity.' The soprano Martina Arroyo, a friend since they both won the Metropolitan Opera auditions in 1958, remembers hearing Bumbry's Salome and being frozen to her seat -- her escort had to point out that the opera was over and the rest of the audience was going home. 'She's always in character onstage,' Arroyo said of Bumbry. 'During periods when she wasn't singing, she kept you involved with her, involved in what she was thinking. During the whole period when (Salome) was deciding that she wanted (Jochanaan's) head, her face was the face of a pouty brat: She was going to get what she wanted. I've seen that on her in person as well,' Arroyo said, chuckling. Bumbry has not relinquished her place at the forefront of the opera world. Today, she is most active as a teacher and a competition judge, with some 14 students who come from around the world to her home in Salzburg when she isn't flying around to see them perform. 'I have so much I have to correct,' she says ruefully. 'So many people do not really know how to teach or how to sing.' end adv sat dec 5 