But despite suspecting she'd had the disease for 12 years, Ronstadt's new memoir, "Simple Dreams," makes no mention of her illness.
Instead, she focused on her career, which earned her 12 Grammy awards and was the only thing she ever wanted do to.
“I can remember sitting at the piano,” she writes. “My sister was playing and my brother was singing something, and I said, ‘I want to try that.’ My sister turned to my brother and said, ‘Think we got a soprano here.’"
"I remember thinking, ‘I’m a singer, that’s what I do,’" she wrote. "It was like I had become validated somehow, my existence affirmed."
“It’s weird, but that’s what I thought,” Ronstadt said. “I didn’t think I was a famous singer. I didn’t think I was a star, or that I could make the waters part -- just that singing was what I was going to do. I thought maybe one day I’d get a job singing in a nightclub, and that would be cool.”
The singer, who revealed her disease to the public in August, said she decided not to mention her illness because she didn't have an official diagnosis when the book went to print.
“It was so great to think that there was a chance that I didn’t have it,” she said. “I was kind of glorying in that reality for a while, you know? But I do and that’s just that.”
Even through her denial, she knew there was something wrong.
“I was struggling to sing for so many years,” she said. “I knew there was something dramatically, systemically wrong. And I knew it was mechanical and it was muscular."
"The brain has to be able to send very, very subtle cues to your vocal chords and get the muscles to vibrate a certain way,” she explained. “I’d aim for a C and I’d hit a G. It’s like my elevator would go to the wrong floor all the time.”
And while the diagnosis was a "holy [expletive]" moment for Ronstadt, she said she hasn't thrown in the towel on her life.
"When I wake up in the morning, I think, ‘I can walk and I can talk, so it’s a good day,’ you know,” she said. “‘Cause there’ll probably come a day when I can’t do those things.”