About 6,000 film extras descended on a Norfolk beach after answering a casting call for a Danny Boyle movie.
The Oscar-winning director shot a concert scene at Gorleston for his new film, inspired by The Beatles.
The comedy has been written by Richard Curtis, whose partner Emma Freud tweeted it was the "biggest film crowd ever shot" in Britain.
Ms Freud appealed for extras in May, with 7,400 people signing up in a day.
Gorleston on Sea now. Shooting big scene for our movie. If you are nearby, come and join us. Concert on the roof of the Pier Hotel. Is incredible. pic.twitter.com/DJzhV1WhGs— emma freud 🔴 (@emmafreud) June 27, 2018
We asked twitter for a crowd to come to gorleston beach for the concert scene in our movie. SIX THOUSAND people have turned up. It’s technically the biggest film crowd ever shot on British soil. We are in awe. pic.twitter.com/igT7T5nEw5— emma freud 🔴 (@emmafreud) June 27, 2018
The director instructed the crowd from the roof of the beachside Pier Hotel, for what he described as one of the film's "key, iconic" scenes.
The unpaid extras had to rehearse for the gig in the as-yet-untitled movie, which stars EastEnders' Himesh Patel and Downton Abbey actress Lily James.
Patel performed a punk rendition of The Beatles' song Help, but the crowd was told to pretend they had never heard the song before as the movie was about a world where the band had never existed.
"We'll ask you to go absolutely bonkers - in greeting the superstar who has come home," Boyle told the crowd.
With the sun beating down on the beach, he warned people to save their energy for when the cameras started rolling.
Cameras were dotted around the area, while a helicopter filmed from the air.
"All I can tell you is in making a film every little bit matters and every single one of you does matter - you'll all be seen," said Boyle.
Richard Curtis said he hoped Gorleston could become the Notting Hill for the next generation.
"I walked down Notting Hill the other day and people are still photographing the blue door, so let's hope the Pier Hotel and Gorleston are the blue door and Notting Hill of the next tranche," he said.
One extra told the BBC: "We go to a lot of concerts, but this is the weirdest one we have ever been to."
Boyle and the stars of the film have been spotted in recent weeks at various other locations across Norfolk, Suffolk and Essex.
No date has yet been set for it to hit the cinema screens.