Continuity mistake: In the scene where Katey and James are in his car after leaving La Rosa Negra, James locks the car door on the passenger side but after he makes a move at her, Katey opens the door without unlocking it.
Continuity mistake: During the dance scene where Katie and Javier dance in front of the white screen (with Katie's parents dancing in the film in the background) the straps of Katie's dress of her left shoulder are sometimes up, and sometimes down. In one shot Javier even pulls down the straps while they were already down in the previous shot.
Factual error: Whenever you see a license plate, it says "Puerto Rico, Isla Del Encanto" (where the film was shot). The movie takes place in Cuba.
Factual error: During the opening credits, as the car is driving to the hotel, the Faro de San Juan and Castillo San Felipe del Morro are notably visible in the background; this is one of the most recognizable landmarks in San Juan, which doubles as Havana in this movie. Although there is a similar fort in Havana, the San Juan lighthouse is distinctively different from the Havana one.
Deliberate mistake: The music in the 50s wasn't, by far, the Shakira pop and hiphop style that the people dance to in the movie.
Answer: Because they were singing revolutionary songs. And at that time was strictly forbidden.