(CNN) -- Johnny Cash was, at heart, a storyteller. In that dramatic, Old Testament voice, he sang songs -- about prisons, about trains, about loneliness and hurt and truth -- and made them his own, sounding as if he'd lived them himself. "Folsom Prison Blues," "One Piece at a Time," "The Beast in Me" -- whether Cash wrote them or not, he made you believe. "That was his chief strength," says Robert Hilburn, the author of a new Cash biography, "Johnny Cash: The Life." "He was always best when he tried to tell his own story, or something he cared about."
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Johnny Cash is the subject of a new biography
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Cash had truth in his voice, but he was master storyteller
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Challenge for biographer to separate facts from fiction
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Cash known for "Folsom Prison Blues," "Man in Black"
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