 Having been asked to write songs for other films and shows, but ending up being rejected because producers favored songs by other artists, Robertson agreed to write the theme only after learning that Lorre and Prady had not asked anyone else.On October 9, 2007, a full-length (1 minute and 45 seconds) version of the song was released commercially.Although some unofficial pages identify the song title as "History of Everything," the cover art for the single identifies the title as "Big Bang Theory Theme."