Damon Albarn has told the crowd at Glastonbury Festival that "democracy has failed us".
On the morning news came through that the UK had voted to leave the European Union, Blur frontman Albarn spoke out about the referendum result.
Beginning his performance with the Orchestra of Syrian Musicians on the Pyramid Stage, the singer said: "I have a very heavy heart today because, to my mind, democracy has failed us.
"Democracy has failed us because it was ill-informed.
"And I just want all of you to know that when you leave here, we can change that decision. It is possible."
As music kicked off across the festival site, Damon told the crowd: "So here we are, Friday. Reasons to be cheerful: It's not raining."
But a light drizzle began shortly afterwards and further rain is forecast to hit on Friday afternoon.
The orchestra first performed with Damon in 2008 and appeared on the album White Flag by his group Gorillaz.
As Syria was torn apart by a civil war, Albarn has sought to reunite the orchestra and chorus for a series of concerts. Many are now refugees.
Damon said: "It's been a miraculous journey but we have somehow managed to gather some extraordinary musicians from the pan-Arabic world.
"Mainly they've come out of Damascus, they've travelled all the way here, from a very different reality.
"One that is very hard for us to really understand. But we've been hanging out for a week, and do you know, the sense of goodwill and positivity that comes out of these people despite what they've been through is truly inspiring."