Marian Anderson was 42 when she sang her legendary open-air concert at the Lincoln Memorial on 9 April 1939. Anderson was a famous contralto of the day, and the concert was arranged after the Daughters of the American Revolution refused to let her perform at Constitution Hall because she was black. (First Lady Eleanor Roosevelt resigned from the DAR in protest and helped arrange the concert at the Lincoln Memorial.) The concert is legendary in the American civil rights movement and, despite Anderson's many other musical successes, became the signature moment in her long international career. Anderson broke many other color barriers, including becoming the first African-American to sing at the White House and at New York's Metropolitan Opera.

Extra credit: Anderson was the aunt of former Oregon Symphony conductor James DePriest... Contralto is the lowest female singing voice, pitched between alto and tenor... Anderson was honored on a stamp from the U.S. Postal Service in 2005... Martin Luther King, Jr. gave his famous "I Have a Dream" speech at the Lincoln Memorial in 1963.