Showcasing the third act of the gods of rock, David Hepworth looks at how enduring icons like Bob Dylan, Bruce Springsteen and Pink Floyd remain on top in the ever-changing music game.

When Paul McCartney closed Live Aid in July 1985 we thought he was rock's Grand Old Man. He was forty-three years old.

As the forty years since have shown he - and many others of his generation - were just getting started.

This was the time when live performance took over from records. The big names of the 60s and 70s exploited the age of spectacle that Live Aid had ushered in to enjoy the longest lap of honour in the history of humanity, continuing to go strong long after everyone else had retired.

Hence this is a story without precedent, a story in which Elton John plays a royal funeral, Mick Jagger gets a knighthood, Bob Dylan picks up the Nobel Prize, the Beatles become, if anything, bigger than the Beatles and it's beginning to look as though all of the above will, thanks to the march of technology, be playing Las Vegas for ever.