Glen Campbell has suffered from Alzheimer’s for about three years now, and last week the 78-year-old country music legend was transferred to an Alzheimer’s facility.

Best known for his huge country hits including Rhinestone Cowboy, Wichita Lineman, and Gentle On My Mind, Campbell is a true legend in the music world. He also had his own TV show on CBS, The Glen Campbell Good Time Hour, which aired from 1969 to 1972.

“He was moved to an Alzheimer’s facility last week,” a family friend told PEOPLE magazine. “I’m not sure what the permanent plan is for him yet. We’ll know more next week.”

Glen Campbell and his fourth wife Kim Whoolen went public with his diagnosis back in 2011 in an interview during which the singer shared his desire to embark on a live farewell tour. They wanted fans to be aware of his condition just in case he messed up lyrics or appeared disoriented at any point during his performances.

The Goodbye Tour launched in 2012, but appearances in New Zealand and Australia were cancelled due to his deteriorating condition. He was able to perform his final appearance on the tour in Los Angeles, however, at the Hollywood Bowl. The L.A. Times music critic Roberts wrote following that performance that Glen Campbell performed with “effortless grace, and had he not announced in 2011 that he was living with Alzheimer’s disease, few in the crowd would have been the wiser. In fact, he was sharper and more precise during this gig than he was last year at Club Nokia, where he kicked off the Farewell Tour.”

The Goodbye Tour was filmed for a documentary called Glen Campbell … I’ll Be Me. It debuts on Friday April 18th at the 2014 Nashville Film Festival. The film follows Glen Campbell along with his wife and three adult children–Cal, Shannon, and Ashley–as they perform together on the road while contending with the progressive stages of his disease.

“I still love making music,” Campbell told PEOPLE back in 2011. “And I still love performing for my fans. I’d like to thank them for sticking with me through thick and thin.”

It’s heartbreaking to watch a music legend lose the ability to do what he loves most. Alzheimer’s is a cruel disease. It robs not only the patient, but those who love him, of the person he used to be.

Image via Wikimedia Commons