U2 wanted to work with Kendrick Lamar because he has a "similar spirit" to them.
The Irish rockers featured on the US rapper’s hit ‘XXX’ and he repaid the gesture by appearing on their tracks ‘Get Out Of Your Own Way’ and ‘American Soul’ on new album ‘Songs Of Experience’, and the group admitted he was "top of [their] list" for potential collaborations.
Band member The Edge said: "It was really just that we were fans.
"We were just thinking about artists we really respect and like, and he was on the top of our list. We look for artists that we feel have a similar spirit."
Frontman Bono added: "There’s a righteous anger that is hard to argue with.
"I asked him would he rap about where America is at, his reply was to rap about where America isn’t at. Smart dude."
Bono is pleased with the direction the group – who have released 14 studio albums – have taken over the years with their latest album inspired by recent political changes, such as Donald Trump’s election and Brexit, and he likes listening to people have "violent disagreements" about U2’s style.
Speaking to Stereogum, he added: "I’ve had people talk to me about what they think is or is not authentically U2. They’re often in violent disagreement with each other and I like that and I’ve had those conversations for 40 years.
"We’ve had some bad haircuts over the years but stylistically, musically speaking, I’m not embarrassed about anywhere we’ve gone. Lyrically, yes. Vocally, yes. But in terms of the present tense, who isn’t curious about what’s going on around them?"