Music fans in Liverpool are to get the chance to enjoy a near-normal gig as part of a government pilot event.
A crowd of 5,000 will see headline act Blossoms without having to social-distance or wear face coverings.
But they will only get into the 2 May event by having a negative Covid test.
Meanwhile, the FA Cup semi-final between Leicester City and Southampton at London's Wembley Stadium will host a crowd of 4,000 later as part of a series of government trial events.
On Sunday, the UK recorded 1,882 new Covid cases and 10 deaths within 28 days of a positive test, according to the latest government figures. The number of deaths recorded over the weekend tends to be lower because of reporting delays.
More than 32.8 million people have had their first dose of a coronavirus vaccine, while more than 9.9 million people have had their second dose.
The outdoor concert at Sefton Park will operate below its capacity of 7,500.
Ticket-holders will be required to take a lateral flow test, which can produce a result within 30 minutes, at a local testing centre before entry, the Department for Digital Culture Media and Sport said.
Attendees will also be asked to take a test after the concert - and will have to provide contact details to NHS Test and Trace to ensure they can be reached if someone who attended tests positive.
Culture Secretary Oliver Dowden said: "We're one step closer to a summer of live events now our science-led programme is under way.
"Testing different settings and looking at different mitigations is key to getting crowds back safely."
"I hope it won't be too much longer until gigs are back for good," he added.
Announcing Blossoms as headliners, Claire McColgan, director of Culture Liverpool, told BBC Radio 5 Live's Breakfast it was nearly two years since the city had held outdoor mass-attendance events.
She said scientists would assess how attendees move and respond during the gig, and voluntary tests taken afterwards will be used to identify any infections that might arise.
"The stuff you see on stage is just a tiny, tiny part of it," she said. "It's loads of people's jobs - it's 60,000 jobs across our city region."
Who are Blossoms?
- Blossoms are an indie-pop band from Stockport, Manchester
- Tom Ogden is the lead vocalist, Charlie Salt is on bass, Josh Dewhurst on lead guitar, Joe Donovan on drums and Myles Kellock on keyboards
- 2016 was a major breakthrough year for the band, when their self-titled debut album landed at number one on the official albums chart
- Their most-streamed songs on Spotify are Charlemagne, There's A Reason Why (I Never Returned Your Calls), and Your Girlfriend
- They were on a UK tour as the coronavirus pandemic struck in March 2020 - with their biggest gig at Manchester Arena cancelled during the first lockdown
- They are hoping to perform at the Victorious, TRNSMT and Kendal Calling festivals later this year
Source: Official Charts, Spotify, and @BlossomsBand
Health Secretary Matt Hancock said the results from the concert would "inform our approach to ensuring future big events can take place safely".
The event will be organised by music promoter Festival Republic in partnership with Culture Liverpool.
Greg Parmley, chief executive of Live, the UK's live music industry body, said the outdoor pilot was "a hugely positive development and brings the summer festival season one step closer".
The government is trialling crowds at a series of events in England. The first of these - the World Snooker Championships - began on Saturday, with a reduced crowd of 213 watching at Sheffield's Crucible Theatre.
Organisers hope the crowd will be at its full capacity of 980 by the final on 2 May.
Other events planned as part of the pilot scheme include other events in Liverpool including an evening at an indoor nightclub, a business conference and a cinema screening.
A mass-participation 6.2 mile (10km) run was scheduled for later this month at Hatfield Park in Hertfordshire but has since been postponed.
Under the government's roadmap for easing lockdown in England, large events can restart from 17 May at the earliest - but with limits on audience numbers - and nightclubs will be able to reopen no earlier than 21 June.
A target date for the restart of large events in Scotland and Northern Ireland has not yet been set.
'Stick to roadmap'
Meanwhile, leaders of the UK's biggest hospitality businesses have signed an open letter to Prime Minister Boris Johnson urging him to "stick" with England's roadmap to reopen the economy.
The letter in the Sunday Telegraph, signed by the chief executives of Mitchells & Butlers, Fuller's, Young's, JD Wetherspoon, Pizza Hut and Alton Towers owner Merlin, said two-thirds of hospitality venues "couldn't open outdoors from 12 April, and none is breaking even".
The signatories added: "The prime minister set out the right path. He should stick to it and not let it be derailed by talk of vaccine passports in pubs and restaurants."
The Night Time Industries Association admitted the reopening of outdoor hospitality in England had led to a "challenging" weekend.
The association's Michael Kill told BBC Breakfast: "As you can appreciate it is a very challenging environment. It's great to be back - it's been a very busy weekend and the majority of customers have adhered to measures that have been put in place by the businesses."
"I think there is going to be a bit of a bedding in period for people to get used to things and for things to settle - particularly over the first weekend," he added.
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