Robert McFerrin
Wiki link: Robert McFerrin
Robert Keith McFerrin Sr. (March 19, 1921 – November 24, 2006) was an American operatic baritone and the first African-American man to sing at the Metropolitan Opera in New York City. His voice was described by critic Albert Goldberg in the Los Angeles Times as "a baritone of beautiful quality, even in all registers, and with a top that partakes of something of a tenor's ringing brilliance."