Singer Glenn Campbell has died at the age of 81. The country singer had struggled with Alzheimer's for years. He's best known for his hits "Rhinestone Cowboy," and "Gentle On My Mind," but this was his final "love song," to his wife. He wrote it a couple of years ago, when he knew his illness meant he'd soon forget the memories they shared. I would have said "Rhinestone Cowboy" was one of my favorites (and it still is), but this song has so much more meaning, and is so powerful, I can't listen to it without getting emotional.