I've noticed a number of stories in the past year or so about music being used to urge on depravity. If you read about Robert Mugabe's Zimbabwe, you'll run across pieces about Khmer-Rouge-style indoctrination camps where inmates are forced to sing cheerful songs extolling the wonders of the Zanu-PF (Mugabe's political party). If you read about the horrors perpetrated in Darfur (here's a brief primer), you'll learn about the women who accompany the Arab Janjaweed militias, singing songs in praise of the torture, murder, and rape inflicted on Sudanese blacks.
In Jamaica, the blood music isn't devoted to one organized political movement. It's against homosexuals; and when I say "against" I don't mean not letting gay folks enjoy the benefits of marriage. I mean explicitly calling for their murder.
An activist who has attempted to draw the attention of Britain's black community to the problem in Jamaican music has been accused of having a "colonial mentality."