The gates of Folsom State Prison closed behind Gene Beley. It was 1968, and it was the first time the 28-year-old had ever been to state prison.

“When you walk through there and they shut that door,” he says, “you realize that many men who have that happen never see their freedom again. It’s pretty daunting.”

Unlike the people he met inside, though, Beley wasn’t there to do time. The young reporter for the Ventura Star-Free Press was there to see country music star Johnny Cash perform for the prisoners.

It turned out to be a historic day. Cash’s January 13, 1968 performance at the California prison wasn’t just galvanizing—it revived Cash’s flagging career, produced a hit album, and has become the stuff of music legend. And Beley, who was one of just a handful of non-prisoners to witness the concert, still feels its reverberations today.

At the time, he says, Cash wasn’t exactly a beloved celebrity. “You know, John was really on the skids,” he remembers. Cash had made a string of bad headlines for doing everything from smuggling pills across the Mexico border to trespassing. He had struggled with drug use, conducted an open affair with June Carter (he ultimately divorced his first wife and remarried), and had even been targeted by hate groups. As a result, newspapers hated him—and he distrusted reporters.

Nevertheless, the Reverend Floyd Gressett, one of Cash’s closest friends, invited Beley and his colleague, photographer Dan Poush, to cover the concert. Only one other reporter, Robert Hilburn, attended.

Beley recalls being surprised that Cash was close to a minister. “It seemed so incongruous,” he says.

In fact, Gressett was the reason Cash would perform at Folsom Prison in the first place. The minister also counseled state prisoners, and asked Cash if he’d be interested in meeting some of them. Cash, who had written “Folsom Prison Blues” in 1953, was intrigued by the thought of meeting inmates—and performing his song at the prison that inspired it. In November 1966, he put on a show at Folsom, and in 1968 he decided to return to record an album.

Before the concert, Beley went to Cash’s parents’ home. There, he met John and June. “My first introduction to them was seeing them walking down this country road,” he recalls. “I wish I had a picture of that.”

Cash, who was dressed in a blue sportcoat and a turtleneck, defied his expectations. “He looked like a movie star,” he recalls. Beley, who had been a fan of Cash’s early hits as a high school kid in Montana, was star struck.

“He was just so down to earth and friendly,” he recalls, his voice softening. “Totally charming, a great smile. He looked like the guy next door—someone you’d want to hang out with.”

Before the show, Gressett played Cash a demo written and recorded by a prisoner serving time for armed robbery named Glen Sherley. It was a song called “Greystone Chapel,” and Cash was immediately moved by it. “I want to record that. I want to record that,” he said. He learned the song and rehearsed it with his band.

On the day of the concert, Beley sat on a bench with the prisoners and experienced one of history’s most remarkable performances. As the sound bounced off the granite walls of the packed dining hall, he watched the prisoners around him.

“It was probably the first time they were allowed to give such emotion,” he says. Encouraged by the emcee to be part of the show, the inmates obeyed, hollering, screaming and singing along.

“It was quite an education,” he recalls. “You know, you visualize murderers and thieves looking like really bad guys. Probably 50 percent looked like the boy next door. They were just like high school kids at a big concert.”

Of course, it wasn’t just any concert. Armed guards surrounded the crowd, and Cash was vitally aware that he was performing for people who couldn’t leave when the show was over.

At the end of the show, Cash announced that he was going to sing a song by Glen Sherley. It was a complete surprise to Sherley, who was seated in the front row. “He jumped out of his chair,” Beley recalls. “I thought his eyes were going to bolt out of his head. I don’t think I’ve ever seen a happier man alive.”

The concert ended up changing Sherley’s life. He recorded a successful live album in prison and eventually got out of jail. He went on to join Cash’s band, but was fired after threatening to kill one of his bandmates. Sherley, who struggled with life outside of prison, eventually killed himself. Cash paid for his burial.

Cash became an advocate for prison reform after recording At Folsom Prison. After the show, he performed at multiple other prison shows, recording a follow-up album, At San Quentin, in 1959, to a prison audience that included future country legend Merle Haggard. “He always identified with the underdog,” Cash’s brother, Tommy, told the BBC in 2013.

Beley kept in touch with Cash after the show, briefly trailing him on the road and conducting other interviews. “I got to see him from many different viewpoints,” he says. “I saw him as the father, the good son.”

Yet he also recalls Cash’s humbleness. “He was almost an ‘aw shucks’ type of guy. You couldn’t ask for anyone more Arkansas, down-home, humble.”

The Folsom Prison album helped revive Cash’s career and reputation, allowing him to turn his outlaw image into an asset, not a professional liability. Beley, for his part, went on to have a long career as a journalist, entrepreneur and newspaper owner. He and Poush still own the rights to the photos and recordings they took that day, and have licensed them widely. “We get little royalty checks every quarter, practically,” he says.

For Beley, the concert was a once-in-a-lifetime event—one he feels lucky to have witnessed. “You never know when one day might impact your entire life,” he says.