Google "worst death metal lyrics" and the results are intense — and mostly unpublishable on this website.
The lyrical themes in the genre have sometimes earned it a bad wrap, and led to concerns it might be morally corrupting, or could desensitise listeners to violence.
In 1980s, conservative groups in the US started campaigning against violence and sexual themes in music, while Ozzy Osbourne and Judas Priest were sued because their songs allegedly led to the suicides of young men.
More recently, Cannibal Corpse has become the focal point in this discussion, and the American band's records — with titles like Butchered At Birth, Gallery of Suicide and Torture — were banned in Australia for several years.
This has all raised a pretty obvious question: Does death metal make you less responsive to violence?
Metalheads don't 'dwell on the violent imagery'
Well, no — according to a new study, published in the Royal Society journal Open Science, by Professor Bill Thompson at Macquarie University and others.
Professor Thompson and his team brought together 32 metalheads and 48 non-metal fans and tested them using a technique called binocular rivalry.
"The beauty of this technique is that it gets at unconscious processing of imagery," he said.
The team presented each person with two images — one for each eye. One image was of something violent, the other of something normal and innocuous. The team hoped to see if the metalheads and the non-metalheads interpreted the two images differently.
What they found was that the brain unconsciously processed violent imagery disproportionately to neutral imagery, likely because of the biological need to recognise a threat.
What's more, said Professor Thompson:
"This occurs both for fans and for non-fans of violent music, which shows that, in fact, there's no desensitisation that is occurring.
"If there were, you would have expected the fans of violent music to not disproportionately process and dwell on the violent imagery."
Death metal fans feel power, joy and peace
Last year, Professor Thompson and Kirk N Olsen, also of Macquarie University, found that fans got a "positive emotional experience" from death metal.
Unlike non-fans, who felt tense, afraid and angry when exposed to the music of bands like Cannibal Corpse, fans felt emotions like power, joy and peace.
"Instead of leaving them feeling hostile, the music helps fans to discharge or distract from their own negative feelings, increase energy levels, and generate powerful, visceral emotional states," the pair wrote.
Other research has found a link between violent TV shows and movies and anti-social behaviour in children.
A study published in 2012 tracked the development of kids who were exposed to "media violence" as three- and four-year-olds.
Four years later, those kids were assessed by their teachers, who rated them as having more anti-social behaviour, including "a lack of remorse, lying, insensitivity to the emotions of others, and manipulating others".
But that study did not involve music with violent lyrics, which has not been the subject of a lot of research.
A study in 2003, which involved 500 American college students listening to songs by Cypress Hill and Suicidal Tendencies, among others, was one of the first to show a relationship between violent lyrics and increased aggressive thoughts and hostility.
However, another study, in 2016, could not find that same association.
What do metal fans and musicians make of this?
The idea that death metal doesn't change your response to violence is not news to people in the metal community in Australia:
"For me, it seems so dumb and obvious that it's not something that needed to be studied."
That's Lochlan Watt, who has sung in bands Thy Art Is Murder and Colossus, and who hosts The Racket on triple j.
"I think there is plenty of people who listen to heavy music as a way to manage their anger" and a find a physical release for it, he said.
He agreed with the insights, from Professor Thompson's studies, about feelings of empowerment and community brought about through metal, saying in many ways the stigma attached to the genre is part of its appeal.
For Watt, listening to death metal is no different to watching a horror film — the lyrics, like a movie script, are often fictious, and enjoying it is not going to turn you into an axe murderer.
Does he feel desensitised to violent imagery?
"No," he said.
"I still squirm when seeing extreme violence in films."
Dave Haley is the same. He plays in the band Psycroptic and runs the touring company Soundworks Direct, which brings to Australia some "very evil-looking and -sounding bands that are full of very wonderful and nice people".
"I've been a fan of the music since I was a kid," he said, "and I would say I am probably more placid than your average person."
He said the results of the study were a "no-brainer". Death metal, like horror movies, is just entertainment. It's shocking for shocking's sake."
"People who go to a horror movie want to get scared, they want the extremity ... the adrenalin rush of something that's the completely out of the ordinary. Death metal lyrics and imagery, it's no different."