Heavy metal in 1996 was a collection of parallel worlds. Alternative metal and industrial rock commanded mainstream attention, groove metal remained powerful, and extreme music developed at a remarkable pace beneath the surface. Bands in Los Angeles, Montreal, Oakland, Brazil and Sweden were barely speaking the same musical language, yet together they demonstrated just how far the meaning of “heavy” had expanded.

Tool’s Ænima became one of the year’s defining records. The arrival of bassist Justin Chancellor completed the lineup that would carry the band forward, while producer David Bottrill helped Tool develop a deeper, more spacious sound. “Stinkfist,” “Eulogy,” “Forty Six & 2,” “Ænema” and “Third Eye” combined crushing riffs, hypnotic rhythms, dark humour and philosophical ambition. Alternative metal had rarely sounded this intelligent or unsettling.

Neurosis travelled even further outside conventional song structures on Through Silver in Blood. Tribal percussion, electronics, samples and enormous waves of guitar turned hardcore and sludge into an immersive ritual. The title track and “Locust Star” helped define what would later be called post-metal, influencing an entire generation of bands that treated heaviness as atmosphere rather than simply speed or volume.

Canada’s Cryptopsy pursued the opposite kind of extremity on None So Vile. Lord Worm’s monstrous vocals, Flo Mounier’s astonishing drumming and the band’s violent technical precision made “Crown of Horns,” “Slit Your Guts” and “Phobophile” standards of brutal death metal. Sweden’s Hypocrisy became more melodic and atmospheric on Abducted, shifting Peter Tägtgren’s lyrics toward UFOs and alien encounters. “Roswell 47” became the band’s signature song.

Sweden also produced two progressive melodic death-metal landmarks. Opeth’s Morningrise stretched five compositions across more than an hour, contrasting acoustic beauty with growled vocals and long, constantly changing structures. The twenty-minute “Black Rose Immortal” remains the longest song in the band’s catalogue. In Flames’ The Jester Race was more concise, joining Iron Maiden-style guitar harmonies to death-metal vocals on “Moonshield,” “Artifacts of the Black Rain” and the title track. Along with At the Gates and Dark Tranquillity, In Flames completed the classic Gothenburg triangle.

Sepultura looked toward its homeland on Roots. Produced by Ross Robinson, the album combined down-tuned groove, Brazilian percussion and recordings made with the Xavante people. “Roots Bloody Roots,” “Attitude,” “Ratamahatta” and “Itsári” made heritage part of the music rather than decoration. The album became Sepultura’s final studio recording with Max Cavalera, whose departure at the end of the year closed the band’s classic era.

Pantera’s The Great Southern Trendkill reflected a band under severe internal pressure. Phil Anselmo recorded his vocals separately in New Orleans while Dimebag Darrell, Vinnie Paul and Rex Brown worked in Texas. That tension fuelled the title track, “Drag the Waters,” “Suicide Note” and “Floods,” producing Pantera’s bleakest and most abrasive album.

Type O Negative moved toward lush gothic romance on October Rust. “Love You to Death,” “Green Man,” “Red Water” and “My Girlfriend’s Girlfriend” surrounded Peter Steele’s voice with layered keyboards and melodic guitars. Marilyn Manson took industrial alternative metal into the centre of America’s culture wars with Antichrist Superstar. Produced by Trent Reznor, the confrontational concept album debuted at number three and turned “The Beautiful People” into an era-defining anthem.

Other major releases showed how broad the year had become: Rage Against the Machine’s Evil Empire, Metallica’s controversial Load, Corrosion of Conformity’s Wiseblood, Edge of Sanity’s Crimson, Cradle of Filth’s Dusk… and Her Embrace and Iced Earth’s The Dark Saga. Metal in 1996 could be technical, tribal, romantic, political or theatrical. Often, it was several of those things at once.