Rosanne Cash grew up as the daughter of country music royalty — but behind the bright stage lights was a dark side.
In this week’s issue of PEOPLE, on newsstands Friday, the Grammy-winning singer-songwriter opens up about her father Johnny Cash’s struggles with addiction to amphetamines and barbiturates — which began, she says, as a way for him to cope with the exhaustion of life on the road during his rise to superstardom in the 1950s and ’60s.
“One day when he came home, it was impossible to connect [with him],” Rosanne, 64, tells PEOPLE. “It was like a door closed. I was 7 or 8. He looked shaky and gaunt, [and he] couldn’t connect. And my mom wouldn’t explain it.”
Amid rising tension in their household, Rosanne’s mother, Vivian Liberto, filed for divorce from Johnny in 1966 after suspecting that he had struck up an affair with fellow country star June Carter, who was a part of his touring ensemble.
“I was relieved they were getting divorced,” Rosanne says. “I remember having this thought, even at 12, ‘Maybe now both of them will be happy.'”
Carter, by then divorced herself, rebuffed Johnny’s proposals until he got clean — which he eventually did around the time Rosanne was 13. Johnny and Carter married in 1968 and stayed together through Johnny’s relapses over the years.
“Did June save him? Oh my God, that’s the myth, isn’t it?” Rosanne says. “How can one adult save another? He saved himself, with his faith and a really strong support network.”
After Johnny got clean, Rosanne says it was like “a whole new ball game.”
“Everything came back into focus,” she says. “[We were] connecting.”
Despite his struggles throughout the years, Rosanne says she “adored” her father, who died in 2003 from respiratory problems connected to diabetes at the age of 71 and whose legacy she discusses in the upcoming 16-hour Ken Burns docu-series, Country Music, set to kick off on PBS on Sept. 15.
In the docu-series, Rosanne also discusses forging her own path as an artist, which she says hasn’t always been easy considering her last name.
“For about five minutes I considered changing my last name,” she says. “Dad didn’t say anything, but he was not into it. Then afterwards, when I said, ‘I’m not going to change my name,’ he said, ‘I am so glad you didn’t do that.'”
Now, she’s passing down that same lesson down to her son Jack, 20 — whom she shares with her husband of 24 years, John Leventhal, 66 — as he contemplates a career in performing. Though Rosanne says Jake “doesn’t want people to know” about his lineage, she recently told him not to fight the inevitable.
“I told him, ‘You’ve got to learn your grandpa’s catalog,’” she says. “It’s important.”
Fans can hear selections from Johnny’s catalog right now on the Ken Burns Country Music Enhanced Playlist Experience on Spotify, which was launched in partnership with Burns as a way to celebrate Country Music ahead of its premiere. The playlist includes 48 songs from Country Music’s soundtrack along with outtakes from the film’s interviews with artists such as Jack White, Dolly Parton, and Dwight Yoakam, who each share their favorite country song of all time.
Country Music’s soundtrack is available now as a five-disc deluxe box set.
For much more on Rosanne Cash’s life, pick up the latest issue of PEOPLE, on newsstands Friday.