years ago, april 9th, 1939, 75,000 people turned out for a public concert that forever changed the landscape of african-americans in music. ♪ >> a quarter of a century later, anderson returned to lincoln memorial, this time singing at dr. martin luther king's march on washington. we see as she sings there, dr. king talked about a dream that day. no one thought the years before that she was barred that we'd ever see dr. king talking about a dream. many things today we'd not