Coronation concert: Five of the best moments - from Kermit to Katy Perry

Olly Murs performed on the night for crowds outside the castle

A line-up of Take That, Lionel Richie and Katy Perry joined a throng of 20,000 in the grounds of Windsor Castle for the King's Coronation concert.

A medley of theatre, ballet, classical and pop music was extravagantly staged on the east lawn in front of the castle.

Kermit and Miss Piggy crashed the performance, as did a huge whale as part of a drone light display.

And Prince William told his father he was proud of him.

• The Coronation concert and street parties in pictures

Watched by an average TV audience of 10.1 million - peaking at 12.3 million - the open air, variety show style production was broken up with interviews and flag waving, while the backstage crew scurried about trying to make it look as seamless as possible.

In case you missed it, here are five of the best moments.

1. Kermit's cameos

Kermit the Frog crashed the event with Miss Piggy who flirted with Paddington actor Hugh Bonneville.

King Charles seemed to like this bit.

He appeared later in the royal box beside Prince Edward waving his arms during Take That's performance.

It's a shame Prince Louis wasn't there as he would have liked this bit.

No-one knows what happened to Miss Piggy.

2. Lionel Richie got the Royals on their feet

He's easy like Sunday morning

Lionel Richie performed Easy Like Sunday Morning and All Night Long, which were simple enough to sing along to because most of us know the words, including Princess Kate.

In his skinny leather jeans and sparkly white jacket, the US star appeared at least half his 73 years.

A few eagle-eyed social media users saw Queen Camilla checking her watch during his two numbers, but she could easily have been fiddling with one of those light up bracelets.

3. A Take That trilogy

Mark Owen, Howard Donald and Gary Barlow of Take That

First there were five of them, now there are three. That doesn't matter though because they've got great tunes and Gary Barlow always steels the show anyway.

In any case, Barlow and his remaining bandmates, Mark Owen and Howard Donald, had three numbers and each got to sing one - which is only fair.

It wasn't clear why Calum Scott, runner-up in Britain's Got Talent, joined them at one point.

4. Katie Perry's frock

Katy Perry in a gold dress

Katy Perry appeared in a gold lamé Vivienne Westwood ballgown, a cross between Vivienne Leigh in Gone with the Wind and that foil that you're given to wrap around you if you've run a marathon.

She sang her hits Roar and Firework. And Princess Charlotte is obviously a fan as she sang along to those.

Reflecting on their performances soon after the show, Perry and Richie were joined by none other than the newly crowned King and Queen for a slightly awkward and surreal segment on the US TV show America Idol.

5. A flying whale

Drones in the sky

Fireworks weren't necessary in the end as it was the drone lights that really stole the show.

During a rather limp version of Simple Minds' Don't You Forget About Me, a huge whale appeared to bask in the sky above.

This section was intended to draw our attention to the environment. Some Simple Minds fans may have been confused as to why this banging tune was turned into a ballad and possibly even ruined for them.

The stage itself was impressive - it looked like a space ship had landed in front of the castle, which was lit up by projections.