The behaviour of rap stars who glamorise violence is leading to children being killed on Britain's streets, London's mayor has said.
The Call the Shots initiative will work with school children
Ken Livingstone said the actions of some rappers made carrying guns and knives fashionable.
He was speaking on Wednesday at the Calling the Shots campaign launch.
More than 300 secondary schools in London have been sent multi-media packs encouraging youngsters to develop a lifestyle away from gun culture.
Mr Livingstone said violent crime was the only type of offence that had not fallen in the last couple of years.
The latest annual figures had shown there were more than a million crimes of violence against people in England and Wales.
"This is the highest figure since records began and that increase is clearly reflected here in London," the mayor said.
"Gun crime, knife crime - they are the only crime categories that continue to rise.
"Some overpaid rap artists swinging around with a gun or knife...the consequences of their behaviour is a kid lying dead in the street."
The Calling the Shots initiative, launched at City Hall on Wednesday, will work in schools and youth centres.
It has been developed by the Boyhood to Manhood Foundation, which works to provide positive role models for boys.