Will.i.am has admitted that he felt “intimidated” by working with U2.
Speaking to NME magazine, the Black Eyed Peas star explained that he was incredibly nervous about being in studio with the Irish band.
He said: "I recorded for a month with U2. Even though I worked with Michael Jackson, their U2-ness intimidated me. I didn't know how to suggest a song from scratch.
"So I co-produced I'll Go Crazy If I Don't Go Crazy Tonight and kept I Got A Feeling for us."
The My Humps hitmaker also spoke about an incident with a fan that proved she knew his lyrics better than him.
He added: "In Japan and this girl came up and says, 'I reckon in Boom Boom Pow you say 'boom' 101 times'. I was like, 'Yeah, right', but said, 'Thank you so much for listening to the song'.
"I got back on the train, counted my booms and she was right. We counted all the booms."