"4 in the Morning" was written by Stefani and Kanal after Stefani finished her "Harajuku Lovers Tour" in 2005. The song was influenced by songs from Stefani's debut album "Love. Angel. Music. Baby." (2004). Stefani listened to ballads sung by Roberta Flack and Billy Idol. Stefani also said that "4 in the Morning" was one of her favorite songs from the album.