The musical genre of Narcocorridos uses sousaphones and accordions to provide a pleasant polka-like backdrop for lyrics that sensationalize the exploits of Mexican drug cartels. There has been a surge of violence against young narcocorridos singers in Mexico, resulting in many deaths and injuries.
There's a parallel between Narcocorridos and American Gangsta Rap, in that some say the music merely tells a story based off real life violence and crime while others say it feeds the very crime it sings about. As with all controversial music, there is an ongoing debate over whether or not the art promotes acts of gruesome violence or simply provides a narrative to illegal goings on. It's known that some corridos performers have actually accepted money from cartels to write about them, perhaps this is similar to paying for advertisement. Regardless, Mexican authorities have taken upon themselves to make Narcocorridos music illegal in certain parts of the country.
This brings up obvious concerns of freedom of speech, but the immediate concern is to limit the distribution of the music. Promotion of the genre has been limited in Chihuaha, with any violators facing fines or jail time. Chihuahua is one of several states that is currently facing restrictions in Anti-Corrido legislation. Prohibition of free speech is a problem throughout the world, but this one seems to be in its own category. One of Mexico's biggest problems is drug-cartel-related-violence, and when shootings happen at concerts it's not just the performers whose lives re in danger. Maybe in this case, free speech can be too much of a good thing.