It is very interesting but sometimes sad to see bands constrained by the limits of their own creativity as well as the expectations of their fans. People still pay to hear Stevie Nicks sell Fleetwood Mac songs out of tune, Elton John has been on his last farewell turn I don't know how many times now, but one thing they all have in common is that the fans will boo, tear down the stadium, and leave if they play anything new.