PASADENA, Calif. (AP) — When Jon Bon Jovi agreed to let director Gotham Chopra follow him with a documentary camera to delve into the history of his band, Bon Jovi, he didn’t anticipate it would catch him at a major low point in his career.

The band was launching a tour, and despite doing all he could do to be vocally ready, the “Livin’ on a Prayer” singer struggled through songs and couldn’t hit the notes the way he used to.

Critics noticed and wrote about it. A review from Pioneer Press in St. Paul, Minnesota, said: “It felt like he had forgotten how to sing.”

In a recent interview with The Associated Press, Bon Jovi said the reaction at the time was “heartbreaking.” After exhausting holistic options, he saw a doctor who said one of his vocal cords was atrophying.

“This was unique. It wasn’t a nodule. The strong (vocal cord) was pushing the weak one around, and suddenly, my inabilities were just exacerbated,” said Bon Jovi. He underwent major surgery and is still recovering.