“Very sad news,” one fan wrote on Twitter. “My brother and I listened to Neil Diamond in the back of the family station wagon growing up. So many wonderful memories with his music. Need a cure for Parkinson’s.”

The creator of such classics as Sweet Caroline, Song Sung Blue and Cracklin’ Rosie said in a statement on his website that his doctor recommended the move.

“It is with great reluctance and disappointment that I announce my retirement from concert touring. I have been so honored to bring my shows to the public for the past 50 years.” The remaining shows were scheduled for New Zealand and Australia beginning in March.

Parkinson’s is a neurodegenerative disorder, meaning it progressively causes nerve cells to lose function and die. Those cells produce dopamine, which coordinates movement. 

Symptoms vary, but often include: resting tremor, which can worsen with stress; slowness of movements; problems with balance; a shuffling gait; limb stiffness; difficulty chewing or swallowing; cramped handwriting; speech changes; apathy and depression; constipation; sleep problems; loss of sense of smell.

Many people with Parkinson’s may also develop dementia or signs of cognitive impairment. “As Parkinson’s brain changes gradually spread, they often begin to affect mental functions, including memory and the ability to pay attention, make sound judgments and plan the steps needed to complete a task,” according to the Alzheimer’s Association.

The average age of onset of Parkinson’s symptoms is 60, according to Johns Hopkins Medicine. (Diamond turned 77 on January 24.)  After making his announcement, Neil Diamond said he planned to continue writing, recording and working on other projects “for a long, long time”.

He thanked his many fans, with a subtle nod to Sweet Caroline: “You will always have my appreciation for your support and encouragement. This ride has been ‘so good, so good, so good’ thanks to you.”

The Recording Academy announced on January 19 that it would present Diamond with its Lifetime Achievement Award this summer.