Glen and his wife Kim decided to talk about it NOW because he's doing a farewell tour in the fall.

Kim told "People", quote, "Glen is still an awesome guitar player and singer. 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?'"

Glen adds, quote, "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." He's also releasing a new album on August 30th. It's called "Ghost on the Canvas".

You may remember a few months ago when we talked about the all-star guest cast Glen assembled for the album. And here's a video about the making of the album. It includes some vintage TV footage of Glen's career. Here it is: