It was a well-known ballad about Camelia the Texan — a woman who smuggles drugs into the United States and then murders her lover in a jealous rage — that got Los Tigres del Norte into trouble.
The wildly popular band played the song — one of their many hits chronicling the lives of drug smugglers — during a packed performance Sunday afternoon in the northern Mexican city of Chihuahua.
In doing so, they violated the one hard and fast rule for musicians who play Chihuahua: No singing about narcos.
Now the band owes $25,000 in fines for violating city law.
The penalty against the Grammy-winning group is another high-profile salvo in Mexico's war against narcocorridos — a popular genre of accordion-driven norteño music that some Mexicans believe glorifies drug trafficking and violence.
A few years ago, Chihuahua leaders made it a crime punishable with fines and jail time to play narcocorridos in public, saying such performances were "acts against public security."
In other parts of the country, radio stations have been pressured to stop playing the songs and some of the musicians who make them have been investigated for links to drug cartels.
"The way things are now with insecurity, we can't permit drug traffickers to be venerated in songs," Chihuahua Mayor María Eugenia Campos Galvan told reporters this week.
The city and its inhabitants, she said, are spending serious resources supporting the police in their fight against organized crime. So it doesn't make sense, she said, "to be glorifying drug traffickers at our parties."
Los Tigres del Norte — whose narcocorridos catapulted them to fame in the 1970s — have long insisted that their work doesn't glamorize drug cartel culture, but simply reflects the reality in Mexico. They also sing about love, the life of migrants north of the border and even U.S. presidential elections.
"We always sing what the people want to hear, and what the people are living," lead singer Jorge Hernandez said in 2009, when the band canceled a planned appearance at an awards ceremony in Mexico City after organizers asked it to skip playing "La Granja," a song critical of the Mexican government's approach to the drug war.
In the years since then, violence in Mexico has only gotten worse — this year the country is on track to record more homicides than in any year since the government began releasing murder statistics in 1997. And bands like Los Tigres del Norte have continued to sing about it.
Some performers of narcocorridos have questioned why other forms of popular art that explore themes of violence haven't come under the same level of scrutiny. Movies and telenovelas about the lives of cartel leaders have long been popular in Mexico, including a new Univision hit series about Joaquin "El Chapo" Guzman, the former leader of the Sinaloa drug cartel.
It is likely that Los Tigres del Norte, which consists of four brothers and a cousin who migrated to the U.S., flouted the law intentionally when they started playing the bouncy first lines of "Contrabando y Traicion," or "Contraband and Betrayal," which chronicles the exploits of Camelia the Texan.
The band also played "Jefe de Los Jefes," or "Boss of the Bosses," another prohibited song that tells the story of a swaggering cartel leader.
"Many chickens that were just born / They already want to fight with the rooster," lead singer Jorge Hernandez crooned. "They wanted to scratch my crown / Those who try have died."
It's not as if the band didn't know about the narcocorrido prohibition.
The members of Los Tigres del Norte were banned from playing in Chihuahua in 2012 after they broke the law by performing one of their most well-known songs, "La Reina del Sur" — "Queen of the South" — which recounts the exploits of a female drug dealer, and which was the theme song for an extremely popular telenovela by the same name.
It's unclear when the ban was lifted and how Los Tigres were allowed to play Sunday's show.
Tweets from concertgoers at the Santa Rita festival in Chihuahua suggest the group's decision to play the songs may have been worth it. Many heralded the band members as folk heroes.