 When the two began working on a song that Stefani stated was too personal, she left to visit Kanal. He played her a track on which he had been working and which became "Crash", the album's final single. The two tried to write new material, but gave up after two weeks. They did not return to work until six months later, when Stefani began collaborating with other artists, commenting, "If I were to write the chorus of' Yesterday 'by the Beatles, and that's all I wrote, that would be good enough to be part of that history." Stefani resumed work with Linda Perry, who invited Dallas Austin, and many other artists, including Outkast's André 3000, the Neptunes, and Dr. Dre. Stefani announced the album's release in early 2004, marketing it as a "dance record" and a "guilty pleasure".
