I just watched this clip from 60 minutes: https://www.youtube.com/watch?v=yNrvXw9juNs&ab_channel=60Minutes
Really quite emotional viewing. It is incredible to watch him turn into the performer he used to be as soon as the music starts or the curtain is raised. It is also touching to see him remember Lady Gaga's name when she walks on stage, and how much it means to her.
But the bottom line for us is: although he is physically quite fit for a 95 year-old and his voice is incredible for someone that old, his Alzheimer's is more advanced than I thought.