The COOL singer is thrilled with the explosive mix of new sounds she co-created with Williams despite her initial reservations after years of writing solely with her No Doubt bandmates.
She says, "When I went to work with Pharrell, I was like, 'What if I don't have any ideas?' But by the end of the first day we'd written this perfect song called CANDY LAMB.
"I was ready to leave it at that but the next thing I knew, we had somehow written HOLLABACK GIRL. Pharrell is amazing."