The organiser of Latitude has said the festival is “close to being the safest place in England today” as thousands of music fans head to the event.
Latitude Festival in Henham Park, Suffolk, is the first major UK festival to go ahead following the Event Research Programme's pilot event at Download Festival in Lincolnshire in June.
Latitude is expected to be attended by around 40,000 excited fans and will be the largest camping festival since before the first national lockdown.
Headliners include Wolf Alice, The Chemical Brothers, Bastille and Bombay Bicycle Club.
The festival is also part of the government's pilot scheme programme and is being used to try out Covid certification at a mass gathering.
Everyone attending must have either tested negative for Covid-19 or have been double vaccinated.
Melvin Benn, managing director of the Festival Republic group, told Sky News he feels “very relaxed, not anxious at all” as the four-day music event gets underway.
He said: “I am really very happy and very relaxed. I hope I look relaxed, I feel very relaxed.
“We had a great night last night. It was a huge party. None of the main stage acts were playing but there is a lot going on in the woods, on the lake and in the theatre area.
“I’m very relaxed, not anxious at all. It is probably as close to being the safest place in England today really.”

Festivalgoers were pictured arriving at the festival on Thursday (July 22) amid the heatwave - but the high temperatures are not set to last over the whole weekend.
Two acts – Irish band Fontaines DC and singer-songwriter Alfie Templeman – have been forced to pull out of appearing at the festival after positive Covid-19 tests.
Mr Benn said it is a “shame” they cannot perform but he suggested the programme has not been badly affected.
He said: “I think most of them (the acts) are existing in a little bubble until they have managed to come and play.
“We did lose a couple but there were people standing by waiting to come and play, so we have managed to replace them.
“It was a real shame for Alfie and for Fontaines and some people would have been coming just for them – not just for them but were really looking forward to them.
“But I think we have got good replacements and the festival overall is just worth coming to full stop.”

A vaccine bus, staffed by NHS workers, has also been set up between the festival campsite and the main arena.
Visitors, aged over 18, can get a first or second dose of the Pfizer or AstraZeneca vaccine on a walk-in basis.
Ronnie Fisher, workforce co-ordinator for the vaccine team, said 13 people were vaccinated on the bus on Thursday and another 11 had been jabbed by midday on Friday.
The next major festival on the Festival Replublic calendar after Latitude is Reading and Leeds in August, with almost 105,000 people due at Reading and 85,000 at Leeds.