Diabolus in Musica (Latin for "The Devil in Music") is the eighth studio album by American thrash metal band Slayer, released on June 9, 1998, by American Recordings. Guitarist Jeff Hanneman wrote most of the album's content, which has been described as Slayer's most experimental. It was the band's first album to be played mostly in C tuning, and named after a musical interval known for its dissonance. Lyrical themes explored on the album include religion, sex, cultural deviance, death, insanity, war, and homicide. Despite receiving mixed reviews from critics, Diabolus in Musica peaked at number 31 on the Billboard 200, selling over 46,000 copies in its first week of sales. By 2009, it had sold over 306,000 copies in the United States. Writing, music, and recording Paul Bostaph returned to Slayer in early 1997 after his short-lived side project The Truth About Seafood, and the band entered the recording studio a few months later. Diabolus in Musica was recorded at Ocean Way Recording, and complete by September 1997. It was scheduled to be released the following month, but got delayed until the middle of 1998, after American Recordings was taken over by Columbia Records. Slayer guitarist Jeff Hanneman described the writing process as, "When we were writing this album I was looking for something to beat; I wanted something to beat, but nothing impresses me right now. Nothing sounded really aggressive or heavy enough to inspire me to beat it, so I just had to come up with my own shit." Adrien Begrand of PopMatters felt Slayer introduced characteristics to its music including tuned down guitars, murky chord structures, and churning beats. He believed these characteristics were adopted in response to the then-burgeoning nu metal scene. Drummer Paul Bostaph claims the album is his favorite as he thought the album was "as experimental as Slayer got". As a result, Diabolus in Musica was described as nu metal, and has also been described as groove metal and alternative metal. Album title and lyrical themes Diabolus in Musica is a Latin term for "The Devil in Music" or tritone. Medieval musical rules did not allow this particular dissonance. According to one mythology, the interval was considered sexual and would bring out the devil; Slayer vocalist and bassist Tom Araya jokingly said that people were executed for writing and using the interval. Araya held concern about the lyrics that King penned to