The debate over the purpose -- and success -- of incarceration rages on today. But in at least one case -- that of J.R. "Johnny" Cash -- prison was a redemptive experience, even if it was just for two musical performances in January 1968. And now, thanks to a traveling photographic exhibit open through Aug. 11 at The Center for Humanities and Arts at University of Arkansas Pulaski Tech in North Little Rock, music fans can revisit the events that reshaped the Man in Black and rewrote music history.