>> what's your biggest fear about this show today? >> that he can't do it. my biggest fear. >> so what about the tour? >> it would be hard to continue to do things. >> my next guest is an american icon. he's won five grammy awards, seven academy of country music awards and three american music awards, sold over 50 million records worldwide. he recently went public with the fact that he'd been diagnosed with alzheimer's disease and he's written a final record as a tribute to his life. tonight he is joined by three of his kids to perform "ghost on the canvas." please welcome the legendary glen campbell. >> thank you. i am happy to be here.