If the 1980s had been the golden age of heavy metal, the age when heavy metal was accepted by the masses and climbed the charts, the 1990s saw the fragmentation of the genre into rather different styles, that simply expanded on ideas of the 1980s.

As usual, pop-metal, the genre that appealed to the masses, was, artistically speaking, the least significant variant of heavy metal. It spawned stars such as Los Angeles' Warrant, with Cherry Pie (1990); Boston's Extreme, specialized in "metal-operas" a` la Queen such as Pornograffiti (1990); and Pennsylvania's Live, with Throwing Copper (1994); etc.

Los Angeles had to live with remnants of its "street-scene" (Guns N' Roses, Jane's Addiction), although they sounded a lot less sincere and a lot less powerful than the original masters. Ugly Kid Joe, Life Sex And Death, Dishwalla, Ednaswap, etc.

Glam-metal staged a comeback of sort in Florida with Marilyn Manson (1), the product of Brian Warner's deranged mind. Propelled by the brutal sounds of keyboardist Madonna Wayne-Gacy and guitarist Daisy Berkowitz, Warner's theatrical exhibition of degenerate, depraved animal instinct wed Alice Cooper's scum-rock and Nine Inch Nails' industrial-hardcore on Portrait Of An American Family (1994). By borrowing the energy of speed-metal, Antichrist Superstar (1996) sold the gimmick to the masses.

Prog-metal

Progressive-metal was more capable of producing new ideas. Notable albums of the 1990s in the style of Queensryche and the likes included: Last Decade Dead Century (1990), by Michigan's Warrior Soul; Wonderdrug (1994), by New York's Naked Sun; etc.

Dream Theater (11), formed at Boston's prestigious Berklee College of Music, established a new standard for progressive metal. Their second album, Images And Words (1992), constructed lengthy melodic fantasias that relied on symphonic magniloquence (Kevin Moore on keyboards), fluid instrumental passages (John Petrucci on guitar), haphazard rhythms (Mike Portnoy on drums) and romantic emphasis (James Labrie on vocals). At the same time breathless and catchy, rock and neoclassical, impulsive and brainy, this style became even more elaborate on Awake (1994), although it lost some of its bite, which got further diluted in the seven-movement suite A Change Of Seasons (1995). At the same time colossal pieces such as Octavarium (2005) became compendia of the prog-rock vocabulary.

In Europe, significant prog-metal contributions included the symphonic metal of Land Of Broken Hearts (1993), by Denmark's Royal Hunt, and the monumental suite Black Rose Immortal, from Morningrise (1996), by Sweden's Opeth (1).

Switzerland's Alboth! (2), a piano-bass-drums trio, invented a new genre at the border between jazz and industrial metal, between Cecil Taylor and Young Gods. The jackhammer rhythms and torrential piano clusters of Liebefeld (1992) and Ali (1996) were both visceral and sophisticated.

Death metal

The terrifying sound of grindcore and death-metal continued to thrive in the USA thanks to New York's Brutal Truth (1), with Extreme Conditions Demand Extreme Responses (1992), Buffalo's Cannibal Corpse, with Tomb of the Mutilated (1992), Louisiana's Acid Bath, with When The Kite String Pops (1994). But Death's Human (1991) led to a "technical" renewal of the field, of which the main proponents were New York's Suffocation on their Effigy of the Forgotten (1991).

However, thanks to the creative work of three American groups, "death-metal" was rapidly mutating into something at the same time more terrible and more musical.

Type O Negative (101) in New York achieved the most shocking fusion of metal, industrial and gothic languages. With vocalist Peter "Steele" Ratajczyck convincingly impersonating a psychopath who uttered nihilist, racist, sexist, fascist invectives, keyboardist Josh Silver molding grandiose sonic architectures, and guitarist Kenny Hickey highlighting the turpitude of the stories with excoriating noises, the terrifying vision of Slow Deep And Hard (1991) acquired a metaphysical dimension besides and beyond its hyper-realistic overtones, bridging the philosophical themes of sex and death the way a black mass would do. Moral ambiguity translated into musical ambiguity, as anthemic choruses wavered like funereal dirges, epic riffs shrieked like agonizing spasms in the struggle for survival, and homicidal fantasies peaked with evil apotheosis. Contrasts and juxtapositions blurred the difference between hell and paradise. Each song was structured as a sequence of movements, each movement arranged in a different fashion, and the sequence leading to unrelenting suspense. They sounded like Wagnerian mini-symphonies composed in Dante's Inferno and supercharged with fear and despair. The apocalypse subsided on Bloody Kisses (1993), a more sincere fresco of urban violence.

Today Is The Day (23), in Tennessee, straddled the border between grindcore, noise-rock, death-metal, hardcore, progressive-rock and industrial music. The visceral nightmares of Supernova (1993) were full of sonic experiments and stylistic twists, but Willpower (1994) went beyond the "ambience" to extract sheer angst from Steve Austin's screams and the trio's assorted cacophony. Each song sounded like a natural catastrophe, each song was the soundtrack of an irrational state of mind. Scott Wexton's sampling machines (replacing the bass player) bestowed an electronic flavor to Today is The Day (1996). The effect was to enhance the progressive-rock part of the equation, a fact that helped sustain the stylistic collage of Temple Of The Morning Star (1997): no less macabre and emphatic, the music also felt surreal and cathartic. It was still the sound of a psychological torture, but one that mirrored some kind of supernatural beauty. After the brief bursts of super-charged grindcore and religious fervor packed on In The Eyes Of God (1999), Austin unleashed the orgy of experimentation of the satanic monolith Sadness Will Prevail (2002), running the gamut from eerie piano ballads to Jimi Hendrix-style cacophony to Middle-Eastern music for radio distortion.

Fear Factory (11), in Los Angeles, painted their harrowing mural of urban decadence with an emphasis on rhythm: thrashing, grinding beats spread like neurotransmitters inside the nervous system of the cyberpunk manifesto Soul of a New Machine (1992). Songs evolved rather than just erupt. The music of Demanufacture (1995), featuring Front Line Assembly's keyboardist Rhys Fulber, seemed to come from another world, saturated with blasphemous truths about this world. Its cascading bombshells kept morphing into cingulate beasts and emanating poisonous miasmas.

This triad pretty much subverted the conventions of the genre, and created a new kind of music, tailored for the issues and the mood of the cyberpunk generation.

A rare attempt to fuse death-metal with progressive-rock and even jazzcore was carried out by Florida's Cynic on their lone album, Focus (1993).

At the turn of the century, the scene was further destabilized by the arrival of South Carolina's Nile (1), the new champions of highly technical and innovative death-metal. Their experiments with keyboards, percussion and ethnic instruments peaked with lengthy pieces such as The Dream Of Ur, off Black Seeds Of Vengeance (2000), and Unas Slayer of Gods, off their supreme In Their Darkened Shrines (2002) that also included the 18-minute four-movement juggernaut In Their Darkened Shrines.

Metalcore

The connection between hardcore and heavy-metal had been kept alive by New York's Biohazard, especially on Urban Discipline (1993), and Boston's Converge, with a series of recordings from Petitioning the Empty Sky (1996) to the explosive Jane Doe (2000). Hatebreed, from Connecticut, established "metalcore" as a major genre with Satisfaction Is the Death of Desire (1997) and The Rise of Brutality (2003). Towards the end of the decade, variants on the same theme were worked out by Missouri's Coalesce (1), who vomited the formidable metal-punk maelstrom of Give Them Rope (1998), and by Massachusetts' Cave In with Beyond HypotermiaHearts Once Nourished With Hope And Compassion (1997), from Florida, managed to sound both catchy and inventive.

Scandinavian black metal

More or less independently of death-metal, a new school of "black metal" arose out of northern Europe, particularly Scandinavia. Notable works included: Entombed's Left Hand Path (1990). Darkthrone's A Blaze In The Northern Sky (1991); Immortal's Battles In The North (1994); Mayhem's De Mysteriis Dom Sathanas (1994); Enslaved's Eld (1997); etc. And add, in England, Cradle Of Filth's Dusk and Her Embrace (1997).

The greatest black-metal band of the decade was probably from Norway, Emperor (1), whose In The Nightside Eclipse (1994) was a concentrate of violence but also a metaphysical (and symphonic) inspection in the otherworld. Among more experimental acts, Ved Buens Ende, also from Norway, wed black metal and post-rock on Written In Waters (1995), and Arcturus, again from Norway, reinvented the genre with La Masquerade Infernale (1998).

New standard for the genre were set by Satyricon's Nemesis Divina (1996), In The Woods' Omnio (1997), Borknagar's The Archaic Course (1998), Carpathian Forest's Black Shining Leather (1998).

Burzum (1), the project of former Mayhem's Christian "Count Grishnackh" Vikernes (now in jail for murder), subscribed to the electronic/ambient version of dark metal with the four massively droning glacial tracks of Hvis Lyset Tar Oss (1994) and Filosofem (1996), containing the monolith Rundtgaing Av Den Transcendentale Egenhetens Stotte: besides providing the demonic vocals, Grishnackh played all the instruments, focusing less on keyboards than on guitars, layered the instruments in a suffocating manner, and set the music to a demented rhythm that subverted the accepted rules of black metal.

Black-metal bands inspired by the Scandinavian masters abounded in other countries: Poland's Graveland, with Thousand Swords (1995), Germany's Nargaroth, with the satanic mass Herbstleyd (1998) and the four colossal suites of Geliebte Des Regens (2003), etc.

Ulver (1) created an "electronic black metal" with the colossal Themes From William Blake's The Marriage Of Heaven & Hell (1998) and Blood Inside (2005), that introduced elements of techno, industrial, ambient and trip-hop music as well as sampled snippets of jazz, blues, classical music, continuously recasting black metal into wildly different frameworks.

A new trend in black metal was orchestral/electronic arrangements: Norway's Dimmu Borgir, with Stormblast (1996), Japan's Sigh, with Hail Horror Hail (1997), Finland's And Oceans, with The Dynamic Gallery Of Thoughts (1998). Tiamat, Therion, and Amorphis pursued a neoclassical version of death metal, which preferred the sound of keyboards. Norway's Theatre of Tragedy even adopted operatic vocals. Haggard introduced symphonic arrangements.

Finland's prolific Circle (1), a mostly instrumental combo fronted by bassist, vocalist and keyboardist Jussi Lehtisalo, adopted a stance that wed progressive-rock, metal riffs, repetitive patterns a` la Steve Reich's minimalist music, "motorik" rhythms a` la Neu, and mystical trance on Andexelt (2000) and Guillotine (2003), while Miljard (2006) removed the "metal" element altogether indulging in quasi new-age atmospheres.

Prog-metal staged a comeback in Scandinavia with the super-technical style of Norway's Solefald (1), which turned Pills Against the Ageless Ills (2001) into a brainy exercise of fusion-metal, and with Pain Of Salvation's One Hour By The Concrete Lake (1999) in Sweden.

Doom metal

"Doom-metal" (a slow, gothic, baroque exaggeration of Black Sabbath's deadly grooves) became more and more popular in England thanks to a number of progressively more sophisticated groups. Paradise Lost, that debuted with Paradise Lost (1990), were the least creative of the founding fathers, but Cathedral (1), featuring vocalist Lee Dorrian (ex-Napalm Death), invented a new format with the lengthy and stately elegies of Forest Of Equilibrium (1991), whose relation with progressive-rock was evident in colossal suites such as The Voyage of the Homeless Sapiens (1994) and The Garden (2006). My Dying Bride (1) perfected that format with an almost baroque grandeur on The Angel & The Dark River (1995). Solstice's second album New Dark Age (1998) mixed epic riffs with Celtic and medieval influences.

America's doom-metal had fewer and lesser adherents: Los Angeles' Obsessed stand out.

The greatest heirs to the throne of doom-metal were still British. Electric Wizard (2), led by singer/guitarist Justin Osborn, inflated the heaviness of doom-metal to the point that music did not flow anymore: it just boomed; a long, dull, oppressive sound. Electric Wizard (1995) blended the holy triad of stoner-rock (Black Sabbath, Blue Cheer and Hawkwind) in a new form that was an implosion of each of them, but its twin album Come My Fanatics (1997) was even more powerful (even heavier, duller, darker and more sluggish), a tidal wave of gloomy sounds. The colossal-oriented approach led to Dopethrone (2000), whose extended tracks towered over an even more apocalyptic wasteland.

During the second half of the decade, bands such as England's Orange Goblin, with Frequencies From Planet Ten (1997), and Sweden's Katatonia, with Discouraged Ones (1998), and especially Beyond Dawn (1), with Revelry (1998), offered other variants on the stereotype.

Super-doom

The Melvins had pioneered a different style, a style that manically emphasized and extended the psychedelic grooves of Black Sabbath. Their "super-doom" grunge was continued in Seattle by Earth (11) were the most extreme of Seattle's "doom-rockers". The titanic instrumental tracks of the EP Extra-Capsular Extraction (1991) and the album 2 (1993) relied on colossal drones and heavy rhythms seen through the distorted lense of Dylan Carlson's neurosis. Earth's music sounded like the casual jamming of extraterrestrial monsters. It merged elements of LaMonte Young's avantgarde minimalism and Eastern music's transcendental ecstasy and drenched them into gothic-scifi atmospheres. They were not "songs", they were hyper-psychedelic states of mind. Phase 3 (1995) and the more accessible Pentastar - In The Style Of Demons (1996) continued Carlson's virtual sampling of historical riffs of hard-rock in a more earthly setting. Compared with their evil symphonies, Lou Reed's Metal Machine Music was classical music.

Karp (1) packed a mad carnival of cacophonous maelstroms, spasmodic psychodramas, rowdy voodoobilly and monolithic trance on Moustaches Wild (1994).

Earth's main followers were Sunn O))) (3), the new project of Engine Kid's guitarist Greg Anderson and Khanate's bassist Stephen O'Malley, particularly on the four monumental concertos for bass and guitar only of Zero Zero Void (2000), even heavier and slower than Earth. By the time they perfected their formula with Black One (2005), via the super-heavy drones and sinister monoliths of cacophony of Flight Of The Behemoth (2002) and White2 (2004), the whole project sounded like the doom-metal equivalent of Lou Reed's Metal Machine Music. Their compositions were studies on how to combine the sound of a guitar and a bass to produce infinite loops of proto-riffs, moebius strips of distorted drones. Rarely had music sounded so ugly and hostile.

Super-doom was not limited to the Pacific Northwest.

Louisiana's Eyehategod (1), who debuted with the ferocious In the Name of Suffering (1990), opened the way to an entire "sludge-core" scene in the South dedicated to truculent, feedback-laden, deep-groove rock music. Texas' Sweet Pea, with Chicks Hate Wes (1996), were among the many that followed suit.

Georgia's Harvey Milk (1) drained the loud, slow, brutal and mean-spirited creatures of My Love Is Higher (1996) of any emotions, carving a niche between Type O Negative, Swans and Melvins.

Stoner rock

"Stoner-rock" was an evolution of Blue Cheer's brutal hard-psychedelic-blues sound: super-distorted, super-heavy and super-loud.

The genre was first pioneered in southern California by Kyuss (11). Wretch (1991), basically, expanded on Chrome's hurricanes from the perspective of hard-rock (Chrome without the new-wave frills), but Blues For The Red Sun (1992) was a majestic work in a completely new dimension, a collection of disturbing symphonies for bulldozers and bombers, with disorienting interludes worthy of acid-rock. The waves of feedback and the cascades of melting steel coming from Josh Homme's guitar, the vibrant eloquence of John Garcia's crooning, the seismic bass of Nick Oliveri and the tribal drums of Brant Bjork, combined to produce the effect of high-tension electroshocks, breakneck gallops and incandescent lava. Welcome To Sky Valley (1994), on the other hand, was almost baroque in the way it fused all those elements into a uniform and organic one, like an act of vanity from a bunch of cannibals.

Stoner-rock thrived in the San Francisco Bay Area. Sleep (1), the band of vocalist Al Cisneros and guitarist Matt Pike, bridged doom-metal and stoner-rock with the slow, dark, booming dirges of Volume One (1992). And then it fell prey to a Black Sabbath obsession on Sleep's Holy Mountain (1993). Everything came into focus (i.e., to a virtual standstill) with the cryptic lumbering hour-long suite of Jerusalem (1998), originally recorded in 1995 and reissued in its 63-minute entirety as Dopesmoker (2003), one of the most austere attempts at scoring the deepest torments of the human psyche, a turgid mass of convoluted guitar monologues and werewolf howls which actually sounded like one deep coma.

The second epicenter of stoner-rock was New York, where Monster Magnet (1), led by guitarists David Wyndorf and John McBain (and later Ed Mundell), concocted a crazy variant of Hawkwind's space-rock on Spine Of God (1991). It almost sounded like a parody of (soon to be called) stoner-rock, but the sound actually became heavier on Superjudge (1993), although Jimi Hendrix's soul-blues blood ran through its veins. These cathartic baths in guitar distortions dissolved into the heavily arranged (mellotron, strings, sitar) Dopes To Infinity (1995) and the more conventional grunge sound of Powertrip (1998).

Ed Mundell's Atomic Bitchwax (1) offered a more experimental version of Monster Magnet's sound on Atomic Bitchwax (1999). Boston's Nightstick (1) even added elements of free-jazz and avantgarde noise to the "Black Sabbath meets Blue Cheer" formula on Ultimatum (1998).

Southern California remained throughout the decade one of stoner-rock's main centers, as proven by works such as Fu Manchu's In Search Of (1996), Unida's Coping With The Urban Coyote (1999), the new project of Kyuss' vocalist John Garcia, and Nebula's Charged (2001).

Queens Of The Stone Age (1), the new band formed by Kyuss' guitarist Josh Homme and bassist Nick Oliveri, offered a consumable version of Kyuss (shorter songs, emphasis on the melody, streamlined dynamics) on Queens Of The Stone Age (1998). After the stylistic experiments of Rated R (2000), they achieved a sort of hard-rock classicism on Songs For The Deaf (2002), featuring Foo Fighters's drummer Dave Grohl and Screaming Trees' vocalist Mark Lanegan, the ideal balance of Cream and Nirvana.

Outside the USA, the main stoners and super-doomers were Japan's Boris (2), whose terrifying monoliths Absolutego (1996) and Amplifier Worship (1998) indulged in the art of transforming colossal riffs into lengthy, dark and extremely dense drones. The five-movement symphony At Last - Feedbacker (2004) oscillated from dark to gentle to manic to ethereal and back, emphasizing texture over atmosphere.

Funk-metal

The real money machine of the 1990s was funk-metal. In the 1980s bands such as Red Hot Chili Peppers and Primus had coined a style that was a hybrid of funk and hard-rock. Earlier, Run DMC had already experimented with a fusion of rap and heavy-metal. These two simple ideas made up the scaffolding of much heavy-metal of the 1990s.

Los Angeles was funk-metal's home turf: Infectious Grooves, the side-project of Suicidal Tendencies' vocalist Mike Muir, with The Plague That Makes Your Booty Move (1991); Eleven, with Eleven (1993); Sugar Ray, with Brownies And Lemonade (1995); etc.

Rap-metal was also headquartered in Los Angeles. Rage Against The Machine (1), the band that launched the style worldwide, realized one of the most important leitmotivs of the decade: a fundamental unity of purpose between the music of black urban rebels and the music of white urban rebels. Rage Against The Machine (1992), one of the most violent albums of the time, a worthy heir to MC5's homicidal fury, sustained seismic shocks after seismic shocks thanks to Tom Morello's guitar explosions (from Hendrix-ian glissandoes to Page-esque hard-rock riffs), Zack de la Rocha's visceral and frantic rapping and ultra-syncopated hail-like rhythms. The sinister and morbid atmosphere of Evil Empire (1996), virtually a philosophical essay on willpower, and the passionate call to arms of The Battle of Los Angeles (1999) reached new depths although they lost most of the bite.

Elsewhere, funk-rock's stars included New York's Scatterbrain, the new band by Ludichrist's vocalist Tommy Christ and guitarist Glenn Cummings, with Here Comes Trouble (1990); Holland's Urban Dance Squad, with Mental Floss For The Globe (1990); Nebraska's 311, with 311 Music (1993); England's Senser, with Stacked Up (1994); Seattle's Presidents Of The USA, with Presidents Of The USA (1995); New York's Orange 9mm, with Driver Not Included (1995); etc.

Angst-metal

Rap-metal turned into something completely different, halfway into the decade, with the advent of Korn (1). Jonathan Davis embodied the post-yuppie pessimism at the turn of the century, and made a career of focusing on the anxieties of disaffected teenagers of the middle-class. Thus the tone of Korn (1994) was bleak, and, while not as aggressive as other funk-metal bands, it had few rivals in terms of dramatic tension. It was only fitting that Life Is Peachy (1996) and Follow The Leader (1998) were confused and insecure albums, compensating a lack of songwriting skills with an emphasis on mood swings and claustrophobic atmospheres.

The intense, macabre, excruciating, self-flagellating music of Korn became the dominant factor. The "post-Korn generation" that dramatically changed the landscape of heavy metal included: Sacramento's Deftones (1), first with the harrowing psychodramas of Adrenaline (1995) and then with the sinister and titanic White Pony (2000); Michigan's Kid Rock (born Bob Ritchie), with Devil Without A Cause (1998); Florida's Limp Bizkit (1), with Three Dollar Bill Yall (1997), driven by Fred Durst's furnace of angst and anger and derailed by DJ Lethal's beats, scratches and samples, and with the ambitious and experimental Significant Other (1999); Sacramento's Simon Says; Boston's Staind; San Diego's P.O.D.; and two more bands from Florida, Cold and Puya. And the usual truckload from Los Angeles: Incubus, with Science (1997); Orgy, with Vapor Transmission (2000); etc.

The Armenian-American outfit System Of A Down (2) was perhaps the most revolutionary of the Los Angeles acts, concocting with System Of A Down (1998), Toxicity (Sony, 2001) and Mezmerize (2005) a sonic experience that was both extremely complex and extremely violent, evoking the punk barricades of the late 1970s with visceral, vibrant political anthems while upping the ante of prog-metal with disorienting rhythmic and melodic turns.

Soul Fly (1), the brainchild of former Sepultura frontman Max Cavalera, heralded an even bolder degree of stylistic fusion (dub, drum'n'bass, hip-hop) with Soulfly (1998) and especially Primitive (2000).

Post-metal

By reinterpreting Dazzling Killmen for the crowd of metal-heads, New Jersey's Dillinger Escape Plan (1), with the unstable metal-jazz compounds of Calculating Infinity (1999), virtually invented a subgenre, a new form of prog-rock with the "heaviness" of metal-punk.

Canada's Strapping Young Lad (1), the brainchild of veteran vocalist Devin Townsend, reached a new level of sonic savagery on City (1997) while coining an influential huge, gloomy sound with industrial overtones.

Sweden's Meshuggah (3) better categorized it as a subgenre of avant-jazz and post-rock with the angular and intricate compositions of Destroy Erase Improve (1995) and Chaosphere (1998), indulging in off-kilter time signatures and polyrhythmic aggression. Catch Thirty Three (2005) was a wildly experimental suite in 13 movements that focused on tape loops and beat machines rather than on guitar riffs and vocal roars.

Ranking among the most creative bands of their generation, Discordance Axis (1) played grindcore influenced by Japanese noisecore on brief albums such as Jouhou (1998) and especially The Inalienable Dreamless (2000).

The Neurosis-sanctioned confluence of grindcore and industrial music, was explored by San Diego-based Tarantula Hawk, on their first album Tarantula Hawk (2000), and by Australia's Berzerker, on their second album Dissimulate (2002).

Other post-metal albums at the turn of the century included: Spiral Architect's A Sceptic's Universe (1999), sleek jazz-metal from Norway, Botch (1)'s second album We Are The Romans (1999), from Seattle, Candiria's fourth album 300 Percent Density (2001), rap-jazz-metal fusion from New York, Mudvayne's more accessible L.D. 50 (2000), from Illinois, and PsyOpus' Ideas of Reference (2004), from New York.