as Obituary, Emperor, Mötley Crüe, Alice in Chains, Pearl Jam, King Crimson, Porcupine Tree and Metallica. However, the band has stated that they are not influenced by other metal bands. The album's first track, "Monolith", refers to Stanley Kubrick's film 2001: A Space Odyssey. The band were greatly influenced by this film during the making of L.D. 50. During the songwriting process, the band members paired riffs with lyrics based on what Matthew McDonough referred to as "number symbolism". According to McDonough, while he and Chad Gray wrote the lyrics to "Nothing to Gein", Greg Tribbett performed a riff which alternated in bars of 4 and 5. Because the number 9 is a lunar number, McDonough felt that the riff would fit the song's lyrics, which referred to serial killer and grave robber Ed Gein, whose actions McDonough associated with nighttime activity. Gein's story grabbed the attention of McDonough and Gray as they were leafing through a book on murderers and true crime. Regarding Gein, McDonough commented, "It seemed so impossible [for Gein] to bridge the gap into mainstream society. I found that exciting that I could find humanity in him". The album's title derives from the technical term 'Median lethal dose', abbreviated 'LD50', used by toxicologists to refer to the dose required to kill half (50 percent of) the members of a tested population. A sound collage entitled "L.D. 50", composed and recorded by drummer Matthew McDonough, appears on the album as a series of interludes. The complete piece appeared as a bonus track on The Beginning of All Things to End, Epic Records' reissue of the band's 1997 self-released EP Kill, I Oughtta. The album also features distorted audio clips voiced by American philosopher and psychonaut, Terence McKenna, who died around the time of the album's recording. The musical style of L.D. 50 has been primarily described as heavy metal or one of its subgenres. AllMusic described the album, in addition to heavy metal, as thrash. Exclaim! described the album as nu metal. Spin magazine has described the album as having a "future-prog" sound. The Rough Guide to Heavy Metal described the album's sound as art metal. Release and commercial performance L.D. 50 was released on August 22, 2000. It peaked at number one on the Billboard Top Heatseekers chart and number 85 on the Billboard 200. The singles "Dig" and "Death Blooms" peaked at No. 33 and