An audio tape of a previously unpublished interview with Martin Luther King, Jr. has emerged, in which King calls the movement "one of the greatest epics of our heritage." The nearly pristine reel-to-reel recording marked, "Dr. King Interview, Dec. 21, 1960," was found by Stephon Tull in dusty boxes in his father's attic in Tennessee. His father was interviewing King that year for a never-written memoir. The practically perfect tape captures King talking about the importance of the civil rights movement, his definition of non-violence, and how a recent trip to Africa informed his views. New York collector Keya Morgan authenticated the tape and is arranging a private sale this month.

While many of King's recordings are known to exist, this one is unusual because there's little audio of King discussing his activities in Africa. Instead, many, including Mr. Tull, are surprised to hear MLK's voice after all these years. "No words can describe. I couldn't believe it," he told The Associated Press this week in a phone interview. "I found… a lost part of history." The interview took place four years before the Civil Rights Act became law, three years before King's famous "I Have a Dream" speech, and eight years before his assassination.