A Perfect Circle (often referred to as APC) is an alternative rock supergroup formed by guitarist Billy Howerdel. Howerdel had worked as a guitar tech for bands such as Nine Inch Nails, The Smashing Pumpkins, Fishbone and Tool. He played demos of his music to Tool's singer, Maynard James Keenan, who offered himself as vocalist should Howerdel ever form a band. Howerdel was initially hesitant about this as he originally wanted a female vocalist, but eventually agreed and A Perfect Circle was formed in 1999. To distinguish himself from his persona with Tool, Keenan wore long wigs on his otherwise bald scalp for all of A Perfect Circle's music videos, photo shoots and live performances. Maynard, when asked at a news conference, stated that the name " A Perfect Circle" originates from the friendships of the band members, all of them met one another in a way resembling "a perfect circle of friendship." The band's latest line-up featured Jeordie White (formerly of Marilyn Manson and Nine Inch Nails tour line-up) on bass, James Iha (formerly of The Smashing Pumpkins) on guitar, and prolific session drummer Josh Freese (also known from Nine Inch Nails tour line-up). Although the group never officially disbanded, A Perfect Circle has been on hiatus since 2006, having not written new material, toured or recorded, but the band's personnel have kept busy with other projects.

30 Seconds to Mars (or Thirty Seconds to Mars) is an alternative rock band from Los Angeles, California, featuring actor Jared Leto as the lead vocalist. Created in 1998 by Jared Leto and his brother, Shannon, 30 Seconds to Mars began as a small family project. Things began to speed up quickly, and Matt Wachter later joined the band as bassist and keyboard player. After working with small revolving door of guitarists (as the band's first two guitarists, Kevin Drake and Solon Bixler, left the band due to issues primarily related to touring), the three auditioned Tomo Miličević to round out the band's roster. According to an interview from Virgin Records, the band's name "actually comes from a thesis that the band found online that was written by a former Harvard professor. And one of the subsections of the thesis was titled 'thirty seconds to mars' and he goes on to talk about the expediential growth of technology that relates to humans and saying that we are quite literally thirty seconds to mars. What it means to us is, we thought it best described our music, in short." 30 Seconds to Mars' first, self-titled album, produced by Bob Ezrin, was released in 2002 to mixed reviews and achieved sales of just over 100,000. The band's second album, A Beautiful Lie, was released on August 30, 2005. For this effort, the band traveled (during the course of three years) to four different continents, including five different countries, to perfect their sound and also to allow for Jared's film career. The album was produced by Josh Abraham, whose producing credits also include Orgy, Velvet Revolver, and Linkin Park. Because A Beautiful Lie was leaked five months before its release, the band decided to include two bonus tracks: "Battle of One" (an original song that was also set to be the album's title track when it was first announced) and "Hunter" (a cover of the Björk song of the same name). To further promote the album, the band also enclosed "golden tickets" in 12 copies, which grant their owners access to any 30 Seconds to Mars concert free of charge, along with backstage access. On August 31, 2006, the band won the MTV2 Award for "The Kill" at the MTV Video Music Awards, one of their two nominations. The second nomination was for Best Rock Video; however, they lost to AFI's "Miss Murder". In the video members of the band reenact scenes from The Shining. A Beautiful Lie was certified platinum by the RIAA in January for distribution of over 1,000,000 albums. In October, the band began their "Welcome to the Universe" tour, sponsored by MTV2. They were supported on this tour by Head Automatica, The Receiving End of Sirens, Cobra Starship, and several other bands including Street Drum Corps. On November 20, MTV2 premiered the video for "From Yesterday"; the video is the first American rock video ever shot in its entirety in the People's Republic of China. The music video is loosely based on the film The Last Emperor. On April 29, 2007, the band performed at the Australian MTV Australia Video Music Awards, where they were nominated for three awards, winning "Best Rock Video" and "Video of the Year" for "The Kill". As of Spring 2007, the band is supporting The Used as a part of the "Taste of Chaos" tour and have scheduled a string of dates in Europe supporting Linkin Park. They are also scheduled to play Roskilde, Rock am Ring, Pinkpop, and Download. Following other commitments, they will begin working on their third album. On March 1, 2007, bassist Matt Wachter announced his departure from the band live on stage during the band's El Paso, Texas "Taste of Chaos" set. This was confirmed the following day with a statement on the band's website. He has since been replaced by Tim Kelleher (not the actor of the same name), who has been seen playing at the band's concerts. It is unknown if this is a temporary or permanent change. Wachter has also since joined Angels & Airwaves. Following the release of "From Yesterday" as a single, the band posted a link on their MySpace blog to vote for the next single from A Beautiful Lie. The choices available were "A Beautiful Lie", "The Fantasy", "Savior", and "The Story". Another vote was done later between the top two songs, "A Beautiful Lie" and "The Fantasy". On May 2, 2007, the band announced that "A Beautiful Lie" had won and would be the next single. On August 8th, 2007, Kerrang! announced that 30 Seconds to Mars has been nominated for two categories of the Kerrang! Awards 2007 - Best International Newcomer and Best Single - The Kill. On August 24th, they had only won the award for 'Best Single,' which was The Kill. The other award was lost to Madina Lake. On November 1, 2007, the band won the MTV Europe Music Award for "Rock Out", one of the two catorgories they were nominated in.

Children of Bodom is a metal band from Espoo, Finland. There is some contention regarding the band's genre classification, but in general the band's musical style can be described as a cross between melodic death metal and power metal (with some concluding this tag only includes their earlier works). Their name was derived from the Lake Bodom murders. The lyrics of Children of Bodom's songs are written in English and are most often concerned with the subjects of death/the grim reaper, personal struggles, war and the Lake Bodom murders. Recent albums have seen a shift to more antagonistic lyrics (songs such as "You're Better Off Dead" and "In Your Face") and a more straight-forward heavy metal style.

Opeth is a Swedish progressive metal band from Stockholm, Sweden, formed in 1990. Led by frontman, and songwriter Mikael Åkerfeldt, the band has released eight studio albums, two live recordings, and a box set. A notable exception in their catalog is Damnation (2003), a pure progressive rock record. Rooted in Scandinavian death metal, Opeth later delved deep into experimentation, having since incorporated influences from jazz, progressive rock, blues, and folk, crossing genre borders to create a blend of musical styles—most successfully with their ground-breaking Blackwater Park (2001), and their latest release Ghost Reveries (2005).

Pennywise is an American punk rock band that was formed in 1988, and is named after the monster It from the Stephen King novel, It. Since Pennywise's 1991 self-titled debut, the band has released an album every two years on Epitaph Records, a label owned by Bad Religion guitarist Brett Gurewitz. So far, Pennywise have released eight full-length studio albums, one live album, two EPs and one DVD. Their last album, The Fuse, was released in 2005. The band is also currently working on its next album, which is due for release in early 2008.

Radiohead are an English rock band formed in Oxfordshire in 1986. The band comprises Thom Yorke (lead vocals, rhythm guitar, piano, electronics), Jonny Greenwood (lead guitar, other instruments), Ed O'Brien (guitar, backing vocals), Colin Greenwood (bass guitar, synthesisers) and Phil Selway (drums, percussion).

Rancid is a punk band, formed in 1991 in Albany, California, by Matt Freeman and Tim Armstrong. Rancid includes Armstrong on guitar and vocals, Freeman on bass and vocals, Lars Frederiksen on guitar and vocals, and Branden Steineckert on drums. The band was formed by Armstrong, Freeman, and former drummer Brett Reed, who left the band in 2006 and was replaced by Branden Steineckert. Frederiksen joined Rancid in 1993 when the band was searching for a second guitar player. They are credited, along with fellow California punk bands The Offspring and Green Day with reviving mainstream popular interest in punk rock in the United States during the mid 1990s. Among mainstream audiences, Rancid is best-known for their hit songs "Ruby Soho", "Time Bomb", "Salvation", and "Fall Back Down". As of 2007, Rancid has been working on a studio album expected to be released sometime in 2008 on Hellcat Records.

Simple Plan is a French Canadian pop punk band based in Montreal, Quebec. The band has released two original albums: No Pads, No Helmets...Just Balls (2002) and Still Not Getting Any... (2004); as well as two live albums: Live in Japan 2002 (2003) and MTV Hard Rock Live (2005). The band is due to release their self-titled third CD on February 12, 2008 (February 6, 2008 in Japan).

The Sisters of Mercy are a rock band that emerged out of the English post-punk scene in 1980-1981. After achieving early underground and goth fame in UK, the band had their commercial breakthrough in mid-1980s and sustained it until the early 1990s, when they stopped releasing new recorded output as a strike against their record company. Currently, the band is kept alive as a touring outfit only. The band's symbol was inspired by a common illustration in Anatomy textbooks, namely that illustrating the anterior and posterior triangles of the neck. Specifically, it was noticed by Andrew Eldritch in the early medical student's bible Gray's Anatomy. The group has released three original studio albums, of which the last was released in 1990. Each album was recorded by a different line-up; singer and songwriter Andrew Eldritch and the drum machines called Doktor Avalanche are the only points of continuity among the line-ups. Eldritch and Avalanche were also involved in The Sisterhood, a side-project connected with Eldritch's dispute with former members. The group ceased recording activity in 1994, when they went on strike against their record company Time Warner, which they accused of withholding royalties and being incompetent. Although Time Warner eventually let the band go in 1997, they have not signed to another label, and have chosen not to go the independent label route, despite showcasing numerous new songs in their live sets. Since 1985, when the other original members left, The Sisters of Mercy has become the artistic vehicle of Andrew Eldritch. Ex-members of the group established the bands Ghost Dance and The Mission.

Six Feet Under (often abbreviated as SFU) is a side project band started by Chris Barnes, founder of Cannibal Corpse, and Allen West of Obituary. Originally, the band was intended to be a side project only, but Chris Barnes decided to pursue the idea of having a groove-laden death metal band that just wasn't about blast beats and speed. In due time, because Chris was making Six Feet Under a priority band, his original band Cannibal Corpse asked him to leave the band, charging that he never made time to practice with them and that he focused more on Six Feet Under than on Cannibal Corpse. Six Feet Under lyrics are usually apocalyptic and brutal, though Barnes' lyrics are somewhat less brutal than that of his past. While their lyrical themes revolve around concepts of violence, gore, and death, many Six Feet Under songs are political in nature and advocate, among other things, the legalization of marijuana, the overthrow of capitalism, and even anti-war sentiment. One notable song by Six Feet Under is their pro-cannabis track "4:20" from their album Warpath. The album's liner notes state that the song (which clocks in at four minutes and twenty seconds) was recorded at 4:20 p.m. on April 20, 1997 (referring to the cannabis related term 420). Six Feet Under has also released two albums of cover songs. The first, Graveyard Classics, is an album of cover songs ranging from Dead Kennedys' California Über Alles, to Black Sabbath's Sweet Leaf, to Jimi Hendrix's Purple Haze, whilst the second, Graveyard Classics 2, is an entire remake of the AC/DC album Back in Black. Guest appearances through various Six Feet Under albums include Ice-T on True Carnage's "One Bullet Left" and Karyn Crisis of Crisis fame on the True Carnage song "Sick And Twisted" (many consider this the first death metal duet between a male and female). Six Feet Under has a strong following in Europe, especially in Germany. In fact, the band also released a special German language version of the song "Bringer of Blood". The last five albums hit the Top 100 of the German Media Control Charts. Six Feet Under have met moderate commercial success, with Maximum Violence being their best-selling record. They figure among the top 5 best-selling death metal bands. World renowned tattoo artist Paul Booth is known to do most of Six Feet Under's album art. The band's line up has remained stable since 1998 when Allen West quit and was replaced by Steve Swanson, formerly of Massacre.

Slayer is an American thrash metal band founded by guitarists Jeff Hanneman and Kerry King. Slayer rose to fame as a leader of the American thrash metal movement with their 1986 release, Reign in Blood, which has been called "the heaviest album of all time" by Kerrang!. The band is credited as one of the "Big Four" thrash metal bands, along with Metallica, Anthrax, and Megadeth. Slayer is known for its musical traits, involving fast tremolo picking, guitar solos, double bass drumming, and shouting vocals. The band's lyrics and album art, which cover topics such as gore, serial killers, Satanism, religion and warfare have generated album bans, delays, lawsuits and strong criticism from religious groups and the general public. Since its debut record in 1983, the band has released two live albums, one box set, two DVDs, one VHS, two EPs, and ten albums, four of which have received gold certification in the United States. The band has received three Grammy nominations, winning one in 2007 for the song "Eyes of the Insane", and headlined music festivals worldwide, including Ozzfest, The Unholy Alliance and the Download Festival.

Slipknot (sometimes typeset as SlipKnoT to fit their logo) are a Grammy Award winning nu metal band from Des Moines, Iowa. Slipknot's roots lie back as early as 1992, however the band wasn't officially formed until November 1995. The band underwent many line up changes before releasing their highly successful début album Slipknot in 1999, during the recording process of which; guitarist Jim Root replaced Josh Brainard, which was the final line up change of the band. The band shot to fame with the release of the album and are considered one of the most popular metal bands of this period. Since which the band have released a further 2 albums and are expected to release a 4th album in 2008. Their albums and home videos have achieved platinum sales status. The band has received multiple Grammy award nominations and won their first in 2006, winning Best Metal Performance with their song Before I Forget from their third album; Vol. 3: (The Subliminal Verses).

Soilwork are a Swedish melodic death metal band from Helsingborg. They are currently signed to Nuclear Blast. Formed in late 1995, originally under the name Inferior Breed, the band changed their name in late 1996 to Soilwork (a play on words meaning, "working from the ground up") to better fit their sound. Their sound is a fusion of the classic Gothenburg metal sound with power-groove riffs of late 1970s, early 1980s British, and European metal. However, in their most recent albums Soilwork have also introduced elements from American alternative metal and adopted a more melodic sound. Their most recent work has more singing and lighter melodies than their earlier work, as well as a more polished production. Because of their more recent changes in sound, they have been likened to their label mates In Flames, labeled metalcore in some instances and even faced scrutiny for "selling out" by fans.

Soulfly are an American heavy metal band from Phoenix, Arizona formed in 1997. Led by founder, frontman, songwritter and only constant member Max Cavalera, the band has released five studio albums, one tour EP, and one DVD video. Soulfly incorporates thrash metal, groove metal, and nu metal with Brazilian tribal music, and world music. The band has had all five of their studio albums debut on the United States Billboard 200, with a peak position at number 32 with their second album Primitive, and the band's debut album, Soulfly, has been certified gold by the Recording Industry Association of America.

Nine Inch Nails (abbreviated as NIN) is an American industrial rock band, founded in 1988 by Trent Reznor in Cleveland, Ohio. As its main producer, singer, songwriter, and instrumentalist, Reznor is the only official member of Nine Inch Nails and remains solely responsible for its direction. NIN's music straddles a wide range of genres, while retaining a characteristic sound using electronic instruments and processing. After recording a new album, Reznor usually assembles a live band to perform with him; this live component is a separate entity from Nine Inch Nails in the recording studio. On stage, NIN often employs spectacular visual elements to accompany its performances, which frequently culminate with the band destroying their instruments. Underground music audiences warmly received Nine Inch Nails in its early years. The band produced several highly influential records in the 1990s that achieved widespread popularity: many Nine Inch Nails songs became radio hits, two NIN recordings won Grammy Awards, and the band has sold over twenty million albums worldwide, with 10.5 million sales certified in the United States alone. In 2004, Rolling Stone placed Nine Inch Nails at 94 on their list of the 100 greatest rock artists of all time. In spite of this acclaim, the band has had several feuds with the corporate side of the recording industry. Trent Reznor announced in 2007 that Nine Inch Nails would proceed independently of record labels. In the past, NIN released major studio albums infrequently; remixes and live albums bridged these gaps in the band's catalog. Reznor cites his personal issues as the cause of these delays, and his songs often confront dark explorations of the self. The most recent Nine Inch Nails album, Year Zero, is an exception to the usually introspective nature of Reznor's songwriting and the long gestation between major releases.