CULIACAN, MEXICO -- In a grassless backyard, an unpolished young band bounces through the classic song, "Pacas de a Kil."Juventud Nortena -- five guys, ages 16 to 25 -- are intent on making it big. They have desire, no little talent, and a monster accordion player in 18-year-old Raul Lopez.The group has mastered several "classics" of norteno music -- a Mexican adaptation of the polka, brought to the region, along with the accordion, by Germans who came to work in breweries more than a century ago. But they are widening their repertory. "We want to learn all kinds of music, so we can get all kinds of gigs," says Lopez.What they lack is a sponsor to buy equipment and get them some concerts. Jesus Garcia, a young taxi driver promoting the band, is blunt. "A lot of these bands are sponsored by some narco (drug smuggler). That's what we want." The band's second original song is a corrido -- a ballad or story-telling song -- about a cousin of singer Rene Bastida, who "is on the wrong path.""We're going to write corridos, you know, about the mafia. That's what really sells," says Jesus Garcia.It's true -- narcocorridos have become the pop music for much of Northwest Mexico. The genre has been a major part of Mexican folk music for at least a century and now the narcocorrido has become a pervasive part of the "narcoculture" in places like Culiacan, capital of the state of Sinaloa.Most corridos tell of historic events -- narcocorridos recount the exploits of drug smugglers, often from the smuggler's point of view. Most include an execution or a shootout between narcos and federales or other bloody events -- all set to a polka beat and the obliviously cheerful norteno accordion line."For as long as I can remember, there have been corridos about bandits, horses, shootouts, fighting roosters," says Jose Nieves, vice president of a record company based here and in California. "But lately it's been all narco."It is possible to see some parallel in gangster rap in the United States -- including Mexico's own Tupac Shakur. Chalino Sanchez, the most famous of the narcocorrido singers, was taken from his car after a show here in 1992. His body was found the next morning, with a bullet to the head. The case remains unsolved.Sanchez was much beloved within Sinaloa narcoculture. "The day after everyone found out, all these guys were driving around town with their speakers blaring his music just waiting for someone to look at them funny," says Federico Sauceda, a staffer at the Sinaloa Commission for the Defense of Human Rights.Today, more than five years later, a number of narcocorrido singers still imitate his raspy tenor. One even calls himself "El Chalinillo" (Little Chalino).Also like gangster rap is the fact that most narcocorridos are never heard on the radio because stations around Mexico have an "understanding" with the government -- yet the music remains enormously popular."This is what sells," says Nieves, standing in his company's record store, surrounded by record posters of shorthaired young men in cowboy hats, gold chains, silk shirts, and ostrich skin boots, standing by fast cars and holding semiautomatic pistols or AK-47s.About 350 bands pass through his offices every year. Album covers depict a staged shootout or drug robbery, complete with young men dressed like those in the posters. The latest called "Soy Crocodrilo Y Que?" ("I'm a Crocodile and What of It?" -- crocodile being slang for cocaine user in this part of Mexico).The demand for narcocorridos is such that most are no longer about real events -- there simply aren't enough to go around -- but most practitioners of the genre keep a close eye on the headlines. By mid-October at least five different bands had recorded corridos about Amado Carrillo Fuentes -- the notorious Lords of the Skies, who died during a plastic surgery operation over the summer.It's not clear how long the narcocorrido trend will last -- the music has a tedious sameness and so many bands have virtually identical sounds, few are able to establish a large following.Still, the cult of the narcotraficante is deep-rooted here in Sinaloa. And narcos consistently have money."Any group that's going to make it big has to be sponsored by a narco," says Jesus Garcia, promoter of Juventud Nortena. "The band that doesn't have a sponsor behind them ends up playing cantinas. We don't want to be playing cantinas."PNS correspondent Sam Quinones is a freelance reporter based for the last five years in Mexico City. This is the second of three reports on Mexico's narcoculture. Photographs illustrating the series are available through PNS -- call George Gundrey at 415-243-4364.