They were the most unlikely rockers but in Northern Ireland these days, anything is possible.
So there they were, David Trimble and John Hume, two middle-aged men wearing ties, on either side of Bono, hands raised, urging a vote for peace. They made the effort, taking their jackets off to reveal colourful shirts.
Bono's words to the crowd in Belfast's Waterfront Concert Hall were simple but emotional.
"I would like to introduce you to two men who have taken a leap of faith out of the past and into the future," and the audience erupted in applause as John and David came on stage.
The two party leaders didn't say anything but they didn't need to. They shook hands and that said it all. For the first time during the referendum campaign they were together on the same platform, delivering the same message. The crowd delivered a standing ovation.
It was a beautiful day in Belfast yesterday as 2,000 young people from schools all over the North made their way to the concert hall on the banks of the River Lagan. "It's wonderful to be here," said Bono as he arrived.
He called for a Yes vote saying: "The extremists have had their day, we are in the next century." Mr Trimble said people had to be optimistic and forward-looking. Mr Hume said the electorate should remember on Friday they were voting not just for themselves but for their "children, grandchildren and future generations".
The girls from Our Lady's Grammar School in Newry took photographs of each other outside the Waterfront. "This is a historic day. I never thought I'd see it," said Aoibhim Higgins.
"It's weird seeing John Hume and David Trimble together but it's good weird," said Emma Edgar from Ballyclare High. On stage, the Downpatrick band Ash read out a statement saying they had been born into the Troubles and they wanted a new tomorrow. To loud cheering, they said there was no alternative to the Belfast Agreement. "We want our country to move into the future. Let's get it together," they said.
But it was U2 the crowd was waiting for. The Waterfront went crazy when Bono appeared. Don't Let Me Down was his opening number. The crowd danced and swayed below the stage and Bono sang: "All we are saying, is give peace a chance."