“Max Martin wrote ‘Bang Bang’ and Ariana was played it, I played it and we both loved it,” recalls Jessie J. “We just said, ‘Why don’t we both do it?’ So Ariana stayed with the second verse, I recorded the first verse, and then Nicki was played it in the studio and said, ‘I have to jump on it.’ We didn’t go to her and ask, she wanted to do it. “

The 33-year-old “Price Tag” singer shared her excitement when she first heard Nicki’s bars for the song. “I’ll never forget: I was in my bedroom in my apartment in London and I got the version with Nicki on it,” she said. “I just sat at the end of my bed with my phone in my hand, stared at the floor and said, ‘How the hell did I get that?’ I literally felt like I had won a competition. “