Music: Celeste Aida

For years great divas have smeared their ample bodies with cocoa-colored grease paint or pancake make-up to sing Aïda, Giuseppe Verdi's Ethiopian princess. This week, an Aïda didn't have to bother. In Mexico City's Opera National the role was sung by Ellabelle Davis, a U.S. Negress.

Her Aïda was a milestone: few Negroes had ever before sung leading operatic roles with white companies. Most great U.S. companies, like the Metropolitan Opera, had never thought twice about such a possibility; "no suitable roles" had long been their stock dismissal of the notion.

Last year, New York's bargain-priced City Opera Company broke opera's rigid color...