NASHVILLE, Tennessee (AP) — A U.S. man says he has discovered the audio tape of a forgotten interview with civil rights leader Dr. Martin Luther King Jr. that was never published.

Stephon Tull says he recently found the nearly pristine reel-to-reel recording in his father’s attic in Tennessee. His father interviewed King in 1960 for a never-written memoir.

The tape captures King talking about the civil rights movement and relations with Africa. New York collector Keya Morgan authenticated the tape and is arranging a private sale.

Raymond Winbush of the Institute for Urban Research says there are few recordings of King speaking about the civil rights movement’s global impact.

On tape, King says of the struggle, “… historians will have to record this movement as one of the greatest epics of our heritage.”