By Steven McIntosh
Entertainment reporter
Katy Perry, Lionel Richie and Take That are among the stars who will take to the stage for the Coronation concert later.
Nicole Scherzinger, Olly Murs, Paloma Faith and Andrea Bocelli will also perform at the event at Windsor Castle.
Hugh Bonneville will host the concert, which is being held to celebrate the Coronation of King Charles on Saturday.
The show will be attended by 20,000 members of the public and air on BBC One and BBC Radio 2 from 20:00 BST.
Other names on the line-up include members of the Royal Ballet, the Royal Opera, the Royal Shakespeare Company, the Royal College of Music and the Royal College of Art.
Crowds have started to build ahead of the concert – with the queue stretching down along the Long Walk to the Castle.
The royal patronages will come together for the first time to create a one-off performance featuring Sex Education star Ncuti Gatwa, who takes over the starring role in Doctor Who later this year, and Olivier Award nominee Mei Mac.
The concert will also feature pre-recorded video sketches from Top Gun star Tom Cruise, Dynasty actress Dame Joan Collins, adventurer Bear Grylls and singer Sir Tom Jones, who will recite little-known facts about the monarch.
Actor Hugh Bonneville, best known for appearing in Downton Abbey and the Paddington films. said he was delighted to be taking part.
“In true British style, come rain or shine it will be a night to remember.”
His involvement is being considered by some as a subtle nod to Queen Elizabeth II, who appeared in a sketch with Paddington Bear for her Platinum Jubilee.
Fashion designer Stella McCartney, guitarist Steve Winwood, and honey enthusiast Winnie the Pooh will also appear, while Bollywood star Sonam Kapoor will deliver a spoken word performance.
The concert will be staged in the east terrace of Windsor Castle. Last week, the BBC released artist’s mock-ups of how it will look.
The corporation said the stage had been designed “with a unique vision to respond to its historic site and occasion”.
The stage will resemble the Union Jack flag, with catwalks jutting out from the centre. It will frame the eastern façade of Windsor Castle, and create multiple levels for the 70-piece orchestra and band.
As darkness falls behind the castle, its façade “will become alive with projection and light”, the BBC said.
The coronation concert will likely attract a huge TV audience, and the those performing can expect a bump in streaming and sales numbers as a result.
But some stars reportedly declined the invitation to perform at the coronation concert for logistical reasons.
Sir Elton John is currently touring in Berlin, while Ed Sheeran is playing a gig in Texas on Saturday.
Kylie Minogue reportedly turned down an invitation to perform because of growing republican sentiment in her native Australia.
Other stars reported to have declined include Adele, who lives in Los Angeles, Harry Styles and the Spice Girls.
Two of the performers at the concert – Perry and Richie – are also judges on American Idol, which is currently broadcasting its 21st season.
As both will be in Windsor for the coronation concert, Alanis Morissette and Ed Sheeran have been booked to serve as guest judges for this week’s American Idol live show.
But Perry and Richie will still appear on the programme, appearing live via satellite from the UK to check in on the contestants.
Tickets were allocated by Ticketmaster via a public ballot, but there was controversy after some members of the public mistakenly believed they’d won tickets after receiving a confusingly-worded email from the company.
Ticketmaster emailed some applicants to say they had been “successful in the ballot for a pair of standing tickets”.
However, to claim the tickets, they had to click on a link to redeem them. By the time many had seen the email they were disappointed to discover they had all gone.
A Ticketmaster spokesman said any unclaimed tickets were released on a first-come, first-served basis to those who had previously applied to the ballot and were unsuccessful.
The company added tickets which had been secured in the first two rounds were guaranteed.