Rap music has been banned at Sydney's Royal Easter Show after a teenager was fatally stabbed at last year's event.
Uati "Pele" Faletolu, 17, was working as a sideshow employee when he was stabbed in his torso after a brawl broke out near the amusement rides about 8pm on Monday, April 11.
He died on the way to hospital.
This year, ride operators are not allowed to play any form of "rapper-type music", used by bikie gangs to recruit "youths", NSW Police Assistant Commissioner Stuart Smith said.
"So the Comanchero bikie gang last year, particularly and proactively procured youths through rapper music," he said.
"They hired a fellow ... and through rapper music investment they procured a significant youth gang problem to carry out violent crime.
"So KVT, Onefour, all those gangs were carrying out serious violent crime on behalf of the Comanchero gang, we've got all the evidence we need to demonstrate that rapper music is being used to lure youth into a life of crime."
Assistant Commissioner Smith said, from their investigations, it was "very clear that these people will not leave each other alone".
Some 30 Public Safety Orders have already been issued to people not allowed to attend the show, and another six will be delivered soon.
The last time the orders were used in such a way was to prevent gang members entering particular suburbs, after crime networks were targeting rival families, Mr Smith said.
The Show's general manager Murray Wilton said other safety measures included increasing the lighting in sideshow alley, using metal detectors, turning music volume down, and banning music with offensive language.
"If you look at the psychology of music ... there is scientific fact the type of music that is played actually predicts somebody's behaviour," Mr Wilton said.
Mr Wilton denied it was a racist move.
University of Sydney Criminology Professor Murray Lee argued there was "little evidence" that rap music incited violent crime.
"You have some evidence, say from the UK, then you've got youth gangs that also just happen to be into rap music and there have been some knife crimes associated with some of that," he said.
"But here in Australia, you'd have to say that the idea that groups like Onefour incites violence seems to be a pretty long bow to draw at this point."
Instead, Professor Lee argued the ban is an example of historic "aesthetic policing".
"The idea that you're going to get a particular reaction from an audience on some ride at the Royal Easter Show because of the type of music being played," he said.
"I mean, I think this really harks back to the moral panics we had around punk music, the moral panics we've had around heavy metal music.
"Moral panics we had about rock and roll and Elvis Presley. This is the latest version of those sorts of panics."
Two teenagers were charged in relation to the murder, which a court heard was related to the "postcode wars" and "youth gangs in Sydney".
Mr Smith said on Tuesday's announcement followed a "comprehensive review" of last year's incident.
"We have been working for months now to make sure this is the safest Show we ever have here," he said.
However, the music ban has already attracted the criticism of an 18-year-old employee, who said it was "stupid".
"I'm a dancer, I listen to rap, and I'm not going around stabbing anyone," Angie said.
Double the amount of police officers will be patrolling the grounds this year, with doors officially opening to the public on Thursday.
