Linda Ronstadt revealed on Friday that she is suffering from Parkinson’s disease, which has left her unable to sing. In an interview with AARP Magazine, the 67-year-old folk-rock veteran said that she had been diagnosed with the disease eight months ago.

Ronstadt said that symptoms of Parkinson’s, which affects the nervous system, began appearing eight years ago, though she initially attributed her ailments to a tick bite and side effects from shoulder surgery.

“I couldn’t sing and I couldn’t figure out why,” she said. “I knew it was mechanical. I knew it had to do with the muscles, but I thought it might have also had something to do with the tick disease that I had. And it didn’t occur to me to go to a neurologist. . . . Then I had a shoulder operation, so I thought that’s why my hands were trembling.”

“No one can sing with Parkinson’s disease,” she said. “No matter how hard you try.” She now uses poles to help her walk on uneven ground and travels with a wheelchair.

Ronstadt’s new memoir, Simple Dreams, is due out on September 17th. According to AARP, she does not discuss the Parkinson’s diagnosis or the loss of her voice in the book.