The crux of this wrecking crew's assault -- as heard on Book Burner, its newest full length for Relapse Records and first album in five years -- is breakneck, eyeball-liquefying, spinal cord-contorting, unholy speed.

We at Crossfade recently spoke with Pig Destroyer's Blake Harrison about being one of the grandfathers of grindcore.

Crossfade: Pig Destroyer is sometimes described as art grind. How do you feel about that term?

Blake Harrison: It is what it is. There are so many genres and sub-genres and sub-sub-genres. If that's what people want to call us, that's fine. I just say we're an extreme metal band. Or a grind band. Or sometimes, even just a fast band. I don't think art grind doesn't fit us. But it's not a term I'd use myself.

But do you agree that Pig Destroyer may be artier than your average grindcore act?

Yeah, I would agree with that. But there are bands that came before us, like Discordance Axis. The Locust were a grind band that used keyboards. There is room in the genre to have other elements involved. I don't know if that answers your question.

Is grind necessarily an angry genre?

I would say so. I wouldn't classify ourselves as necessarily angry people. But you gotta have some kind of fire in your belly. It's not about feelings. Or I guess it is.

It's very much about feelings.

Nihilistic ones.