Singer Linda Ronstadt says she has Parkinson's disease NEW YORK (Reuters) - Grammy-winning singer Linda Ronstadt is suffering from Parkinson's disease and says she can no longer "sing a note," the group AARP said on Friday. In an interview with AARP to be published next week, Ronstadt, 67, said the Parkinson's diagnosis she received eight months ago had given her an answer to why she couldn't sing. "No one can sing with Parkinson's disease," she is quoted as saying in her interview with the lobbying group for older Americans. No matter how hard you try. AARP said she has poles to help her walk on uneven ground and uses a wheelchair when traveling. Parkinson's is very hard to diagnose, so when I finally went to a neurologist and he said, 'Oh, you have Parkinson's disease,' I was completely shocked. I wouldn't have suspected that in a million, billion years," she says in the interview. Ronstadt has won nearly a dozen Grammy awards and sold more than 100 million albums worldwide, according to Simon & Schuster, which is due to publish her memoir this year. The Arizona-born singer's 1974 record, "Heart Like a Wheel," yielded hits including "You're No Good," "When Will I Be Loved" and "It Doesn't Matter Anymore." The soft rock album soared to No. 1, selling more than 2 million copies, according to the AllMusic reference website. Reporting By Edith Honan; Editing by Xavier Briand