From an early age, Tomas' contribution to metal would be significant. As a teen, he was a metal maniac, heavily involved in the underground tape trading scene. Even without his own music, he left prints: it was he who actually designed the iconic logo for Norwegian black metal mainstays Darkthrone.
His first band, Grotesque, in whom he took on the name Goatspell, were one of the first Swedish death metal bands, earning praise for their Ripped From The Cross and The Black Gate Is Closed demos in the late ’80s, and 1990’s killer Incantation EP.
It was with At The Gates, however, that he would help leave the greatest impression. Formed in 1990 in Gothenburg, their Gardens Of Grief EP the following year announced them as heavyweights among their home country’s blossoming death metal scene alongside contemporaries like Entombed, In Flames, Dark Tranquility, Dismember, Grave, Unleashed. People spoke of a shared sound of those bands who came from Gothenburg – there was a vibe all of their own, a more strange darkness, further explored on 1992's essential The Red In The Sky Is Ours debut.
"There was a lot of hanging out watching horror movies and stuff like that," Tomas told Kerrang! of the Gothenburg collective. "There was definitely a scene, but when you talk about the 'Gothenburg sound', everybody shied away from that a little bit because no-one wants to be lumped in as part of a sound. We did it in different ways but I think we all had the same idea of wanting to make something more of death metal. Not just what had been done before but reaching out a bit further, adding more classical melodies.”
At The Gates' reputation and influence would grow on 1993's With Fear I Kiss The Burning Darkness and Terminal Spirit Disease in ’94. It was 1995's Slaughter Of The Soul that would cement their legacy, however. A savage but precise collection of ultra-taut, razor-sharp metal that mixed death metal's brutality with an icy sense of melody, it was by Tomas' iconic coarse screams that brought a chilling quality to his intelligent lyrics.
“With Slaughter… we wanted to make a record that would – in our minds – make some sort of impact," he explained. "Because I think at that point in the death metal scene there was a little bit of stagnation. We thought, 'Let's make something important here.' Our idea was to compress the stuff we had done before to shorter, sharper songs and rehearse them so they were tighter. There was a lot of hard work behind it, but we felt it was now or never because we had some harsh touring situations right before, and Earache [Records] had picked us up from the gutter basically.”
They would split not long after, but almost immediately the style of songs like totemic single Blinded By Fear, the title-track and Cold could be heard in a new generation of metal and hardcore bands, not least Slipknot, who openly praised the band. When groups like Killswitch Engage, Lamb Of God and Unearth began to emerge, meanwhile, first comparisons were to ATG, while Converge invited Tomas to contribute to a cover of Entombed's Wolverine Blues.