The Glastonbury Festival has opened with a sombre tribute to MP Jo Cox.
Portishead's haunting cover of Abba's SOS was shown on video screens before music began on the Pyramid Stage.
The video closed with Cox's quote: "We have more in common than that which divides us."
Blur's Damon Albarn then took to the stage with members of the Orchestra of Syrian Musicians and began with a reference to the EU referendum, saying he had "a very heavy heart".
"To my mind, democracy has failed us," he said. "Democracy has failed us because it was ill-informed. I just want all of you to know that when you leave here we can change that decision. It is possible."
His comments were met with a resounding round of applause.
He then introduced his ensemble, which comprises members of the Syrian National Orchestra for Arabic Music (SNOAM) who were dispersed by the country's brutal civil war.
Their Arabic-flavoured music highlighted the truly global nature of the festival, which will see sets from Korean funk band Sultans of Disco, Australian psych-rock group Tame Impala and even Basil Brush.
Speaking after his performance, Albarn told the BBC he was "really sad" about the referendum.
"I rang my daughter this morning and said: 'I am really sorry this has happened', because the consequences of it are more for her generation than anyone.
"There are seeds being sown today that are really dangerous, and that's what I'm so upset about. We don't want Europe returning to the 1930s.
Manchester band James, who were supposed to be the first act performing on Friday, had their set delayed as woodchip was laid in front of the mud-strewn Other Stage.
'Heart and soul of Glastonbury'
Glastonbury organiser Michael Eavis appeared to apologise for the wait, telling fans: "Thank you for loving this festival as much as we do. You're the best audience in the world."
As the heavens opened, he then cut a ceremonial red ribbon stretching the length of the stage, allowing James to finally begin 50 minutes late.
They dedicated the song Sometimes to the 80-year-old festival organiser, saying: "When you look into his eyes you understand the heart and soul of Glastonbury."
Perhaps inadvertently, the song also contains the lyrics "endless rain" and "come on thunder, come on thunder!".
James also referenced the Leave vote during their set, and later told the BBC they were "pretty upset" by the result.
"As a band, we're pretty European in nature," said frontman Tim Booth.
Pompeii lyrics changed
"There's something important about humanity accepting other tribes and other cultures. It started with the end of slavery, then women's votes, then gay marriage - [occasions] where we didn't see other people as the enemy. I feel sad that Britain has gone back to being an island, in a metaphorical way."
Pop band Bastille also referenced the results in a live session for BBC Radio 1, changing the lyrics to their hit single Pompeii to: "And the pound came tumbling down."
Singer Dan Smith said he feared the vote could have implications for British musicians touring Europe.
"We're lucky enough as a touring band to be playing two or three festivals in different European countries every week and it's so easy. We can get on a ferry and go there, and it's something we've always taken for granted.
"But now I imagine there'll be loads and loads of red tape. Getting visas for every country."
The mood lifted as the day went on, with the sun coming out to greet pop star Jess Glynne's ebullient set on the Pyramid Stage.
"Two years ago, if someone told me I'd be on this stage, singing to this many people, I'd have been like, 'shut up'," said the star.
As well as her own hits, Rather Be, My Love and Hold My Hand, she played a cover of Prince's I Feel 4 U in tribute to the US musician, who died in April.
The Sonic Stage saw a grime-only line-up, resulting in the bizarre site of crowds chanting "South East London, South East London", in the middle of a farm in rural Somerset.
French pop act Christine and the Queens gave an energetic, choreographed performance on The Other Stage; while Norwegian newcomer Aurora drew an appreciative crowd to the John Peel tent.
The rest of the day will see performances from Foals, Disclosure and rock legends ZZ Top, who told the BBC they had been "in the queue to get up and perform" at Glastonbury "for going on five years".
Frontman Billy Gibbons, who was wearing ZZ Top-branded wellington boots, said he wasn't put off by the conditions underfoot.
"I think there'd be some disappointment if you weren't stomping through mud up to your ankles," he said.
"But I've been looking across the landscape. As far as you can see there's a sea of humanity ready to rock."
After ZZ Top, Muse will headline the first night of the festival. Adele and Coldplay top the bill over the rest of the weekend.