Paul Gray, bassist with Slipknot, died last week (May 24).

Ross Robinson produced the band’s early albums. Here, he explains why Gray will be missed

When I heard that Paul had died, I hoped it was a rumour. I didn’t want to believe it – I’d talked to him not long before, and he seemed so excited about the prospect of having a baby. He also had plans to start a new project with Mick (Thomson, Slipknot guitarist), which he wanted me to work on.

Paul and I, we had the best experience anyone in music could ever have. We had a lot in common, partly because we grew up in the same part of the country, where it’s all welfare; basically the lowest level of human existence. On top of that, Paul lost his father at a young age – an experience that I always thought came through in his music.

Obviously people will focus on the circumstances of his death, and the drugs – but Paul’s heart was absolutely pure. When everybody is showering you with love, you need a mechanism to deal with it, and I guess he just felt unworthy of it. He never lost that sense of abandonment. The five-year-old inside him could never get over the fact he’d been left alone.

I don’t think he deliberately took himself out [took an overdose]. The last time I saw him, he told me how good he was doing. Admittedly he never let me into the dark – but Paul knew that recovery was available. He knew he had somewhere to go.

My standout memory of Paul? Finishing the ‘Iowa’ album, and standing with him and Joey [Jordison, Slipknot drummer] in my living room, just sobbing. That was such a powerful moment, one I will always have deep in my heart. God, that guy wrote the most unbelievable riffs. He was the weapon of that band, and nobody knew it.

As a musician, he brought absolute integrity. When he pulled on a guitar, a transformation kicked in. His eyebrows would go down, his brain would switch off, and the music sang through him. He played bass and guitar left-handed, and there was something about his muting, a weird sort of backwards quality. It’s so easy to be generic or cheesy in metal, and Paul never was. There was just something huge coming through him.

At his funeral I saw the band together for the last time, his bandmates acting as pall-bearers. I can’t imagine anything more beautiful than that. It took me to my knees. Take the human story of brutality away, and you’re left with love. That’s what Slipknot stood for.