MARIAN ANDERSON: (Singing in German). LLOYD SCHWARTZ, BYLINE: What I heard today, the great conductor Arturo Toscanini said the first time he heard American contralto Marian Anderson, one is privileged to hear once in a hundred years. And so Anderson came to be called the voice of the century. It's not an overstatement. Just hearing that rich, three-dimensional sound, both high and deep, is profoundly moving. But whether in Bach or Schubert, opera or spirituals, that voice also communicated the most heartbreaking and heart-easing feelings. Her exceptional qualities were more widely recognized in Europe, where, for the most part, her race was not a barrier. In the United States, she had to wait until she was nearly 58 years old before she finally sang her first opera. It was a landmark debut. Her role was the chilling fortune teller in Verdi's "A Masked Ball," a part previously sung only by white singers in dark makeup.