Erotica is a concept album about sexuality and relationships. Each track explores a different facet of sexuality, usually involving sexual relationships. Lyrically, the album does not tie sex and sexual relationships with the traditional ideals of romance. A dance record by all accounts, the album showcases hip hop and jazz-affected club production from co-producers Shep Pettibone and André Betts. It is interesting to note that the song "In This Life" is based on George Gershwin's Prelude No. 2. Madonna's intentions were that the album would be an accompaniment to her book Sex, which share the same cover photograph - a colored reverse negative of Madonna's face done à la Andy Warhol, from whom Madonna found much inspiration during her so-called "Erotica period" (for example, her "Erotica" and "Deeper and Deeper" videos were shot in near identical style to many of Warhol's films, with Madonna paying obvious homage to Edie Sedgwick in the latter). The photos included in the album's liner notes also come from the Steven Meisel Studio photographs shot for the Sex book. The album is Madonna's first album to bear a "Parental Advisory" label (the only other albums to do so being 2003's American Life and 2007's The Confessions Tour). A separate "clean" version was released without the sexually explicit song "Did You Do It?" Originally, "Bad Girl" was planned as the second single from the album with an X-rated video to match the '"Erotica" single, but it was changed due to the backlash of the Sex book and instead it was released as the third single. Madonna performed "Erotica", "Fever", "Bye Bye Baby", "Deeper And Deeper", "Rain", "Why's It So Hard" and "In This Life" on her 1993 The Girlie Show Tour. Early versions of some of the songs on the album, as well as demo versions of songs that were not included, were included in The Rain Tapes - a collection of songs registered during the album development stage.