song without my input, it doesn't feel honest." At the 2007 MTV Video Music Awards, Simpson gave MTV a sneak peek of the album, describing the sound as being more beat-based in contrast to her previous guitar-driven sound. Simpson revealed the record was completed in November 2007, but that she was also continuing to write in anticipation of a March 2008 release. Music and lyrics Bittersweet World contains influences from 70s and 80s music, particularly synth-pop and new wave. Simpson said she was inspired by women like Chrissie Hynde, Debbie Harry and Pat Benatar, because "they are strong and vulnerable simultaneously, yet they still make you want to dance." The Timbaland-produced "Outta My Head (Ay Ya Ya)" has been compared to the sound of Missing Persons. Simpson said the song is a get-out-of-my-head track, saying, "I just have too many voices in my head, everyone having their own opinion." "Boys", written with Chad Hugo and Kenna, is a pop disco song. "Boys" was likened to "The Cardigans' 'Lovefool' atop a Chic rhythm", while People called it "the best Kylie Minogue song that Kylie never did". "Little Miss Obsessive," "Rule Breaker," "What I've Become," and "Ragdoll" stick more to Simpson's rock roots, with "Ragdoll" described as having "a 'Beat It' vibe" and featuring "Casio-esque keyboard tinkling and driving guitars". “Rule Breaker," a "Pat Benatar-like fist-pumper", was named by Rolling Stone as one of the 100 Best Singles of 2008. Of "Rule Breaker," Simpson said it was an attempt to "capture that badass feeling you get sometimes after watching a movie like True Romance. You think you can take on the world and you want to color outside the lines and get a tattoo or mouth off to someone way bigger than you". Rolling Stone noted "What I've Become" as an "excellent coming-of-age anthem" and "a paparazzi kiss-off with an appealingly honest chorus: 'I’ve just begun to find my way.'" Billboard characterized "Murder" as having a "dark, hypnotic groove", and is "filled with beats and synth lines". Simpson said the lyrics of "Murder" "aren't serious, based on a true story or a threat....It's a metaphor about a girl who can get away with murder because of who she is." Like "Murder", Simpson has said "Hot Stuff" "is meant to be a fun song.... A lot of things on the record are laughing at situations, poking fun at things. With that, when you