But after boogieing her way through 19 songs in two hours   at Hope Estate on Saturday night, the only explanation she had for what she had just seen was “black magic”. The fountain of youth. Some very expensive medical treatment unavailable to mortals.

“He shouldn’t be able to do that at that age,’’ she said, marvelling at the sheer energy, charisma and movement that poured out of the 71-year-old Jagger.

 In the 1980s, then the once radical Rolling Stones stumbled into middle age, a once adoring music media  began deriding them as the Strolling Bones. For a long time, their shows were dismissed as cabaret.

But this was no karaoke night, even if the packed crowd recognised almost every song after one note and knew every lyric, lick and drum shuffle along the way.

As guitarist Keith Richards, also 71, is fond of saying, no-one questions why the black blues greats who inspired the Stones originally were still on stage as old men.

And so shouldn’t they, if they enjoy it, and the public is prepared to fork over the cash to hear them?

There’s no doubt Jagger’s a freak. As a woman beside me said when he’d stripped off his jacket, “He looks ripped under that tee shirt.”

I’d bet he still has a 28 inch waist and could slide into his ‘70s stage clothes if the fancy took him. He might have been forced to cancel a Victorian show earlier this month, but he was back to his high-octane self on Saturday, prowling the stage and keeping the distant rows of the hillside crowd up and rocking with a cavalcade of hits.

 And Keith? No longer the world's most elegantly wasted human being,he’s more like a favourite uncle, more unpredictable than deranged, and full of a grinning grace that  says, quite truly, that he's happy to be alive.

Elsewhere on stage, the understated Charlie Watts, looking little older at 73 than he did at 25, wore his usual bemused smile.

Ronnie Wood, still rooster-haired at 67, kept a trademark cigarette glued to his lips and raced around the stage like his usual impish self.

Mick Taylor, who replaced the tragic Brian Jones in 1969 and then walked out five years later to be replaced by Woody, came on for Midnight Rambler and Satisfaction. Having aged normally,Taylor’s crumpled presence only highlighted the eerie otherworldliness of his erstwhile band mates.

 With their long-time supports – bassist Daryl Jones, keyboard player Chuck Leavell, backing singers Bernard Fowler and Lisa Fischer and saxophonist Tim Ries, the 21stcentury Stones are at once comfortably louche but technically tight.

There were some bum guitar notes in some of the early numbers and the laughter between band members – writ large on the clearest big video screens you could wish for – showed they were enjoying themselves playing “somewhere we haven’t been before”, as Mick put it.

  The sound was clean but not defeaning.

The show opened and closed with the traditional rocket fireworks and when the spotlights lit the crowd, even the expensive ticket holders were out of their seats and rocking along. Always a good sign that.

Highlights, for me, were an electrifying Gimme Shelter – Lisa Fischer was simply awesome – the choir-led You Can’t Always Get What You Want, and Keith’s turn at the mic for You Got The Silver.

 My only wish is that Keith sang Happy instead of Just Can’t Be Seen for his third number. He does love to sing it, but from where I stood in the middle of the crowd, it was the only flat spot in a stellar night from the greatest rock and roll band in the world.

Jumpin’ Jack Flash

Let’s Spend The Night Together

It’s Only Rock ‘n’ Roll

Tumbling Dice

Dead Flowers

Rocks Off

Paint It Black

Honky Tonk Women

You Got The Silver (Keith Richards vocal)

Before They Make Me Run (Keith)

Just Can’t Be Seen (Keith)

Midnight Rambler (with Mick Taylor)

Miss You

Gimme Shelter

Start Me Up

Sympathy For The Devil

Brown Sugar

Encore

You Can’t Always Get What You Want  (with Sydney Philharmonia)

(I Can’t Get No) Satisfaction (with Mick Taylor)