 Stefani 's No Doubt bandmate Tony Kanal invited her to his house so that the two could go out with friends . When she arrived , however , Kanal surprised her by playing some tracks on which he had been working and revealed that he had prepared some for Stefani . Though Stefani had wanted to work with Kanal , she was concerned that his work would not fit with her dance @-@ oriented album ; however , she called it her " favorite track that [ she had ] written so far " , and the two worked on the track , modeling it after hip hop trio Salt @-@ n @-@ Pepa . 
