This towering anthem finds Eminem teaming up with Gwen Stefani. The pair recorded the track for the soundtrack of the boxing movie Southpaw. The No Doubt frontwoman recalled how the collaboration came about to Entertainment Weekly. "The process was really simple," she said. "One of his guys came and played me the song and then I was like, 'Yeah, I like it! Amazing!' she said. "I've always wanted to work with him - he's a genius - and then all of a sudden they called me and said, 'It has to be done today' and I was like, 'Ah, my voice' - I had a cough or something. I went in and I made it happen, but it was like, barely."
Stefani is now happy with how the song turned out. "It was like, 'God, why does today have to be the day my voice is not happening?' But it ended up turning out good," she noted. "I wanted to do something with him for so long and I feel honored - he's very selective."
Stefani admitted that when Eminem called her out of the blue to thank her for doing the song, the songstress was expecting an expletive-laden conversation to take place. "I'm driving, literally driving in the minivan with all my kids in the car... and on Bluetooth, somebody calls. And I'm like, 'Hello?' And it was him!" she said. "And he's like, 'Hey just wanted to say thanks for doing the song. And I was like, 'You don't understand- I have all my kids in the car. You can't call me right now. All my kids are in the car! Don't say any bad words!' I was literally going to soccer practice. But I was like, 'I'm gonna make your song so cool!'"