Fans of the late singer Johnny Cash are remembering the concert he recorded exactly 50 years ago - performing before an audience of inmates inside one of America's toughest prisons.
The event highlighted the harsh conditions they endured - and made Cash a country music legend.
It was one of many prison performances Cash gave during a career that made him one of country music's most admired artists.
Al Jazeera's Tom Ackerman reports.
