Miami ? Cuban punk rocker Gorki Aguila is irreverent, vulgar – and bolder than any other performance artist in modern Cuban history.

His lyrics blasting the Cuban dictatorship are so strong, the Miami Herald can’t print too many of them. The founder and lead singer of the 10-year-old group “Porn for Ricardo” walks around the streets of his western Havana neighborhood with T-shirts that say things like, “59: Year of the Mistake.”

In a case that has drawn attention around the world, the 39-year-old rocker went on trial Friday on charges of “pre-crime social dangerousness” that could send him to jail for up to four years.

Wire service reports from Havana said the singer yelled “freedom!” as he was led into a courthouse. Diplomats, human rights activists, artists and journalists swarmed the municipal courthouse Friday morning awaiting the trial, which began some eight hours late. Some family, friends and political activists chanted Aguila’s name as he arrived in a police car and was escorted inside the building, the Associated Press reported.

The trial was closed to the media, and it was unclear late Friday whether the trial – ignored by the Cuban papers – had begun, or whether judges held a simple arraignment.

It came a day after his bandmates were briefly detained during a concert in Havana on Thursday night featuring singer Pablo Milanes, who had been urged by hundreds of artists to publicly call for Aguila’s freedom.

Aguila could become the first artist to face criminal charges for his resistance music since Raul Castro took over power from his brother Fidel two years ago. Castro took over after his brother’s illness in a fanfare of reform, publicly saying it was time to air complaints.

Artists and intellectuals spoke out publicly about past wrongs, and Raul Castro officially welcomed it. But Aguila’s direct attacks on the Castro brothers and his profanity-laced lyrics appear to have pushed the limits on what the Cuban government was prepared to accept.

Cuba watchers say Aguila’s arrest sends a clear signal that while Raul Castro is open to public debate, he will set boundaries.

“It’s one thing to say, ‘the government makes mistakes’ or ‘this thing doesn’t work,’ said Uva de Aragon, of Florida International University’s Cuban Research Institute.

“Going directly after Raul and Fidel is something else.”