It's just a fact of life. Once you're in your seventies, you're obviously onto your final stretch. I went to see Dylan last time he played the Palladium and wish I hadn't. Don't get me wrong, I knew exactly what to expect, but I was still disappointed. It wasn't song choices, or anything like that, it was the fact that Dylan had to basically talk his way through the set, he remained seated for 95% of the gig, the exception being when he shuffled, and I mean shuffled, into the middle of the stage to take a few bows. I've seen the Rolling Stones twice, and while Mick Jagger is something of a marvel, Keith Richards can hardly play, and is reduced to strumming the odd chord. I wouldn't go and see them again, even just for the nostalgia or the 'event'. Springsteen is coming around in the summer, and even though he is more in the Jagger vein, than the Richards, in terms of still being able to perform, his voice is nowhere near what it was, and he is also someone who has drastically reduced the amount of movement on stage. Van Morrison is another artist who I still follow live, and although his voice has held up well, it still is nowhere near what it once was. I get it, these artists are just human, age catches up with all of us. Fair play if they still enjoy performing and people still get some enjoyment from it but also fair play to Mark if he'd rather stop altogether than to make the concessions all the above have made in order to keep performing.