 In 2003 , Stefani began recording solo material . She stated she was considering recording singles to be used on soundtracks , continuing her collaborations or releasing an album under the pseudonym " GS " . Jimmy Iovine ( chairman and co @-@ founder of Interscope ) convinced Stefani to work on this album . On the second day of her sessions with Linda Perry , the two wrote a song about Stefani 's writer 's block and fears about the solo album . This became the track " What You Waiting For ? " . which was released as the lead single for the album . 
