In my decades as a rock critic, that may just qualify as the strangest climax to a concert I have ever witnessed. Amidst balloons and fireworks, Her Majesty Queen Elizabeth II and Prince Charles joined Sting, Shaggy, Kylie, Sir Tom Jones, Craig David and a choir featuring comedian Harry Hill and former Labour Minister Ed Balls onstage at the Royal Albert Hall to be serenaded with a burst of Happy Birthday.
When it was decided to throw a party for the Queen's 92nd birthday, I am not convinced anyone actually considered asking her what kind of entertainment she might like. While I can't claim to know what the Queen listens to for personal pleasure, I'm pretty sure it's not Sting and Shaggy.
Or, for that matter, almost anyone else on the bill. I would have liked to have binoculars to inspect the royal expression when Jamaican toaster Shaggy went walkabout in the crowd, Mr Boombastic toasting the occasion with his lusty dancehall patois, but I think the Queen’s mastery of the poker face is fairly well established by now.
The Queen's Birthday Party - in pictures
At least Her Majesty's loyal subjects in the audience did not have to endure any act on a very mixed bill for too long. This was essentially an excuse to revive the Royal variety show and it moved along at a fast lick, operating a one song and you’re off policy. A few of the more mercenary stars seized the occasion to plug their new singles on prime time BBC (hang your head, Kylie) but most entered into the spirit of the occasion.
The biggest screams of the night were not for Harry and Meghan but for Canadian teen idol Shawn Mendes, looking very dapper in a grey suit and black guitar. British pop starlet Anne Marie on the other hand looked like she thought she was attending a Smash Hits pyjama party. Occasionally I could see Prince William lean over and whisper in his grandmother's ear, possibly to explain what she was witnessing, or apologise on behalf of his generation.
But some curatorial attempt had evidently been made to span musical decades and play the guest of honour some songs she might actually be familiar with. Jamie Cullum made an impression with a swinging version of I Get A Kick Out Of You in which he kicked over his stool, picked it up and waved it at the Royal box.
Laura Mvula followed on piano with a steamy version of Nina Simone's I Put A Spell On You, with some ripe horns and velvet strings from the BBC Concert Orchestra. Operatic baritone Alfie Boe’s lusty swing medley was better received than it really deserved to be. But when Craig David tried to get a singalong going, the multi generational audience proved reluctant unite in homage to the hits of naughties garage 2 step.
It wasn't all western pop music. The Indian drummers of The Dohl Foundation achieved the rare feat of drowning out Sir Tom Jones on a genuinely unusual version of It's Not Unusual. The Welsh Belter fared better with South African choral group Ladysmith Black Mambazo on The Green Green Grass of Home.
It has to be said, though, that the sound at the Royal Albert Hall wasn't very impressive, with vocals mixed low and often drowned in echo. I suspect the considerations of the live audience, even including the Royal family, played second fiddle to the technical demands of a TV broadcast.
Oddest performance of the night came when Ed Balls and Harry Hill joined comic Frank Skinner and the massed banjos of The George Formby Society. But it was Shaggy who got really got the crowd going, throwing himself into the stalls whilst apparently ageless superstar Sting led the band in a medley of hits. The unlikely duo might just have stolen the show, if they hadn't been fittingly upstaged in the surreal finale by the weirdly serene appearance of her Majesty herself.