Glen Campbell is now in the advanced stages of Alzheimer's disease, but in a new interview, his wife says that following his diagnosis with the disease, it gave him pride to embark on his final tour and work on his last song.

After being diagnosed with Alzheimer's in early 2011, Campbell went out on his farewell tour, though his family, friends and doctors were concerned about how he would fare on the road. To the surprise of many, however, the singer was able to maintain his presence onstage, even when he wasn't doing so well out of the spotlight. In an interview with the Tennessean, Kim Campbell recalls a late-2011 performance on Conan O'Brien's show, before which her husband rehearsed two songs -- and then forgot what he and his band had decided to play.

"We didn't know if he would even go on," Kim Campbell remembers. "But when they called his name, he played it just like they practiced."

A Look Back at Glen Campbell's Career

Campbell's willingness to share his story with his fans was met with enthusiastic support, and his farewell tour sold out across the country. Still, as Campbell's illness continued to evolve, his wife had to face the hard reality that she could not be his primary caregiver. The stigma surrounding Alzheimer's patients and their families, Kim Campbell says, made the situation a tough pill to swallow, though she eventually realized what many family members-turned-caregivers do: "You can't do it all by yourself. So don't be a martyr."

Kim Campbell notes that her decision to re-locate her husband to a full-time care facility in 2014 is one that she believes that he would have supported. Glen Campbell was honest about his Alzheimer's journey, sharing what went on during the early stages of his illness in the 2014 documentary Glen Campbell: I'll Be Me; the film's soundtrack includes the Grammy Awards-winning song "I'm Not Gonna Miss You" -- Campbell's final song.

"Glen thought that was probably the most important thing he could ever do," Kim Campbell says of the tune and the documentary. "And I think he’s right."

On Friday (March 24), three of Campbell's most iconic albums -- Galveston, Gentle on My Mind and Wichita Lineman -- will be reissued on vinyl for the first time in decades.

Glen Campbell Through the Years

More From WKDQ-FM