Dignam was diagnosed with cancer in March, and Bono has visited him in his house in Dublin and sent a card when the Aslan singer was receiving treatment in hospital.
It was reported yesterday that Bono will participate in a charity night to raise more than €100,000 to go towards medical expenses in the Olympia Theatre in Dublin.
The event takes place on Friday, and acts include Shane MacGowan, Paul Brady, and Horslips.
U2 will link to the event via satellite from their studio in New York.
Christy Dignam’s daughter Keira, also a singer, will perform at the event, and she told a Sunday newspaper that the fundraising event was Bono’s idea and that the U2 singer also visited the Dignam family home last month, alongside his wife Ali.
“It’s not about publicity, going out to see him, or writing to him. It’s a personal thing,” she said.
“They are married men with families who are passionate about music. It was such a lovely thing to do.
“Bono sent him a lovely letter too, just saying that he and Ali were praying for Dad and he said the loveliest things, it was so nice.”
U2 will perform Aslan’s ‘This Is’ during Friday’s event and the show will be streamed live on the internet. All the acts, which include Bressie and Jedward, will perform an Aslan song of their choice and all monies raised after costs will go towards Dignam’s medical costs.
Keira said she hoped her father would be well enough to attend the event.
“Bono rang up Dad and organised it and that’s how it happened,” she said.
“It was him who asked so that was just great. It has grown legs, the whole concert.”
She added that her father was having good and bad days and he hoped to be at the Olympia on Friday.
Bob Geldof’s Boomtown Rats turned back the years yesterday as they appeared on stage together for the first time in 27 years.
And the 61-year-old Dubliner told thousands of revellers at the Isle of Wight Festival: “It’s been the best fun I’ve had in almost 30 years.
He told the crowd: “We are The Boomtown Rats, we are marvellous, we are magnificent, we are the living Mount Rushmore.”
The band played hits including ‘Like Clockwork’, ‘She’s So Modern’, and ‘Someone’s Looking At You’.
And an emotional rendition of ‘I Don’t Like Mondays’ brought cheers from the crowds.
Geldof told fans: “When we started playing these songs again it was sad because it wasn’t nostalgia, it was like it was 30 years ago, not being able to get a job, the banks ripping you off.”
After finishing ‘Rat Trap’, Geldof said to the crowd: “Thank you very much, it’s been the best fun in 27 years.”
And in an unusual move for a mid-afternoon band, The Rats came back for an encore.