By Chris Boyette, CNN
(CNN) - In a dusty old attic in Chattanooga, Tennessee, Stephon Tull was rummaging through dilapidated boxes left there by his father many years before, when he came across an interesting find.
In one of the battered boxes was an audio reel marked, "Dr. King interview, Dec. 21, 1960."
"I'm a rummager, a packrat," said Tull. "That piqued my interest."
Tull acquired a reel-to-reel player and listened to what sounded like his father interviewing Dr. Martin Luther King Jr. about nonviolence and the civil rights movement.
"I could not believe what I was hearing," said Tull.