Paul Gray: Bassist and songwriter with controversial nu-metal band Slipknot

The bass guitarist Paul Gray was a founder member of Slipknot, one of the scariest-looking, most brutal sounding bands to come out of the US in recent years.

When they first emerged in the late 1990s, many critics, myself included, dismissed them as the latest link in a chain of shock rockers stretching back to the pioneers of the genre in the late Sixties, Arthur Brown in the UK, and Alice Cooper in the US, and the cartoon characters of KISS in the Seventies.

Yet there was something much darker, much more sinister at the heart of Slipknot's music and their freak-show concert appearances, as if they embodied the nightmare the American dream had turned into. Nine- strong and wearing hideous latex masks – Gray originally opted for a pig model – that could have come straight out of slasher films like The Texas Chainsaw Massacre, Friday The 13th and A Nightmare On Elm Street, they made insanely loud, deeply unsettling music, a collision of the heavy metal, thrash and industrial genres which became known as nu-metal.

Despite limited airplay – "People = Shit" was never likely to endear itself to radio programmers – Slipknot soon captured the imagination of would-be rebellious teenagers the world over and their popularity grew apace, thanks to relentless touring and exhaustive coverage of their antics in magazines such as Kerrang!, Metal Hammer and Rock Sound. Indeed, their rabid fans, known as "Maggots", bought enough copies of Slipknot's eponymous debut in 1999, and the "Wait And Bleed" and "Spit It Out" singles in 2000, for their alternative heroes to make the UK charts. The following year, Iowa, the group's second album named after their home state, went to No 1 in Britain.

In 2002, they triumphed at the Reading Festival, and caused a commotion wherever they made in-store appearances. Their uncompromising stance and refusal to remove their masks in public contributed to their mystique and endeared them to their huge international fanbase. Produced by Rick Rubin, best known for his work with Red Hot Chili Peppers and the Beastie Boys, and issued in 2004, Vol. 3: (The Subliminal Verses) proved just as successful, and also contained the thunderous single "Before I Forget", for which they won the Grammy Award for Best Metal Performance in 2006. Two years later, they released the dark All Hope Is Gone, their last studio album to date.

Born in Los Angeles in 1972, Paul Dedrick Gray moved to Des Moines, Iowa with his family a few years later. In the mid-1980s, he rebelled against the Bible Belt mentality of the area and became obsessed with the heavy metal of Black Sabbath and Slayer. He began playing bass left-handed and joined local bands with such ludicrous names as Anal Blast, VeXX, Body Pit and Inveigh Catarsi, and then teamed up with percussionist Shawn "Clown" Crahan in various outfits known as Painface, The Pale Ones and Meld.

In 1996, drummer Joey Jordison suggested a fateful and final name change to Slipknot, the title of one of the tracks that appeared on their self-financed, limited edition demo Mate. Feed. Kill. Repeat. issued at Halloween the same year. In an attempt to force audiences to concentrate on their music rather than their looks, Crahan convinced the others to wear masks.Their striking, ghoulish image greatly enhanced their visibility and marketability. They later added orange boiler suits and also use numbers (Gray was #2).

By the time Slipknot had signed to Roadrunner Records in 1998, they also comprised vocalist Corey Taylor, turntablist Sid Wilson, guitarists Mick Thomson and Jim Root, percussionist Chris Fehn, with Craig "133" Jones taking care of programming and samples. The line-up would remain constant for the next 12 years.

Hiring Ross Robinson, who had already produced Korn, Limp Bizkit and Sepultura, to oversee their first album proved a master stroke, and Slipknot never looked back, even surviving the débâcle that was the 2002 remake of Rollerball, in which they had a cameo performing "I Am Hated" from Iowa, also co-produced by the band and Robinson. In 2003, "Wait And Bleed" fittingly featured on the soundtrack to the satirical horror movie Scream 3.

That year, Gray crashed his Porsche in his home town and was found in possession of small amounts of marijuana and cocaine. He was sentenced to a year of informal probation for drink-driving. However, his police mugshot was posted on the internet, allowing fans to see what he looked like. In 2004, he replaced the Pig mask with a Hannibal Lecter-style contraption. He had recently been collaborating with members of Judas Priest and Sepultura in the supergroup Hail! "Slipknot is my life. It's everything," he once said. "Without Slipknot, I'd probably be sleeping on someone else's couch, working at the bar I used to work at."

He was found dead in a hotel room in Urbandale, a suburb of Des Moines. His wife Brenna is expecting their first child.

Paul Dedrick Gray, bass guitarist, songwriter: born Los Angeles 8 April 1972; married; died Urbandale, Iowa 24 May 2010.