in the glen campbell movie that came out a few years ago, there was a scene where he was on stage and following along on the teleprompter and it said "glen solo" or something like that. his disease was very advanced by this point and he read it out loud like it was part of the lyrics, then realized what it really meant and he tore into a fine solo. his facility on the guitar when his mental condition was so poor hints at how great he was and how deeply music was rooted in him. its not an easy movie to watch at points but very much worth watching