Bono paid tribute to his mother in a song on U2's new album Songs of Innocence.
The singer admitted that is was "excruciating" writing the material for the new record as it was all autobiographical and he didn't want to leave anything out.
He told Q magazine: "It's challenging stuff. What that meant was nothing, nothing was to be kept back. So you end up with a song about - I mean, how f***ing embarrassing is this? I write the lyrics to a song about my mother.
"It was like, 'Are you gonna go there?' So I went there. Here's a wild thing - my mother collapsed at her father's graveside 40 years ago yesterday and I've just sent out a love song to her.
"It's pretty excruciating stuff."
