Though Campbell was diagnosed six months ago, the 75-year-old "Rhinestone Cowboy" singer, who hosted The Glen Campbell Goodtime Hour on CBS from 1969 to '72, is just going public now in advance of his upcoming farewell tour.
"Glen is still an awesome guitar player and singer," explains wife Kim, who was also interviewed by the mag. "But if he flubs a lyric or gets confused on stage, I wouldn't want people to think, 'What's the matter with him? Is he drunk?'"
Says Glen: "I still love making music and I still love performing for my fans. I'd like to thank them for sticking with me through thick and thin."