Johann Hari: The future of Cuba? Ask its rappers ...

They express their frustration through rap, secretly recorded and sold as bootleg

In the middle of a stormy Caribbean summer, a few tears in the intestine of an old man have made two twinned cities - Havana and Miami - awkwardly, anxiously combust. The physical decline of Fidel Castro has been dreaded or dreamed of for nearly 50 years. Now it is here the kinetic energy crackling between these opposing poles of the Cuban imagination - the two-thirds of the population imprisoned on the island, and the exiled lump 90 miles away in Miami - is now more intense than ever. They are gazing at each other across the Caribbean Sea asking: what Cuba comes next?

Power appears to have been ceded to Fidel's brother, Raul, in an ironic moment of communist monarchy. But he has only offered a single robotic statement to state television with the sparsest of information for his new subjects, while offshore, Condoleezza Rice has renewed an offer to lift the suffocating American embargo in exchange for open elections.

Since Fidel was hospitalised, most comment has focused on these top-level state shenanigans. But buried beneath this, there is the ordinary voice of the Cuban people, ignored, as ever.

To the outside world, Cuba has always been as much a symbol as a country - either a plucky icon of resistance to the American Empire or the last frozen gulag of Communism. One side sees the terrific schools and hospitals, the long life expectancy that is far better than in comparable countries with US-backed governments, and the cruel American embargo blocking all trade with the island. The other side sees the political prisoners, the ban on the internet, the firing squads, the driving-out of millions of innocent people.

But now, if you listen carefully, there are whispers of a future Cuba, beyond these sterile, one-eyed polarisations. The fascinating new documentary, East of Havana, which premiered at the Edinburgh International Film Festival last week, offers us an insight into this world through the most unexpected of mediums - rap.

In the cracked, fading barrios that circle the Cuban capital, the children of the Special Period have been shrugging off state censorship and expressing their frustration through rap, secretly recorded and sold as bootleg.

They have lived their entire adult life in the period that began with the fall of the Soviet Union, when the moribund communist-Cuban economy stopped being lubricated with money stolen from the Russian people. They have never known anything but rolling blackouts and families flinging themselves into the sea on rafts to flee.

While they fear the designs of the Bush administration, they also rap to Fidel: "For you to live is to die as a historical figure/ To drag an entire country to the grave with you." They are the Buena Vista Social Club with their eyes open, and these eloquent, dignified young Cubans refuse to shut up. Rap groups like El Cartel have become to Castroism what the Plastic People of the Universe were to Czech communism - a musical outlet for political rage. They long for something like European social democracy or a Chavista revolution - a marriage of social and political rights.

Intriguingly, there is a parallel movement of liberal Cuban exiles who say that "both sides of the Florida Straits are fighting against our own dogmas." East of Havana was made by a team of siblings called Juan Carlos Saizarbitoria, Jauretsi Saizabitoria and Emilia Menocal, and I met up with them last week. They are thirty-something Cuban-Americans, and their life-story is a parable about the mirror-image intolerance of many of the Cuban exiles seething in Miami. The first generation of Cuban exiles fled in 1959 when the Cuban revolution toppled the dictator Fulgencio Batista, who had all the thuggishness and none of the decent social programmes of the Castro regime.

But Juan, Jauretsi and Menocal's grandparents made up a very different wave of exiles that followed over the next decade. Their grandfather owned a newspaper and a famous restaurant that supported the revolution and lauded Castro, believing his promises that he would hold democratic elections. But once the dictatorship began, the newspaper was swiftly shut down by Castro's goons, and the family was forced to flee. They opened an exact copy of their restaurant in Miami and tried to keep alive the dream of a left-leaning democratic Cuba.

But they found fanatical opposition from some of the exile community. In 1996, they booked one of the few native Cuban performers allowed to travel, Rosita Fornes, to perform in a cabaret. This was a massive taboo, seen as funnelling money into a tyranny. The restaurant was firebombed by enraged exiles. "We had our restaurant taken from us twice," explains Juan. "Once by Castro and the hard left, and then by the exiles and the hard right."

Menocal says softly: "Our generation of exiles needs to start a new conversation with native Cubans of our own age."

But the way to smoothly achieve a convergence on true Cuban democracy is not, they argue, through Condi's current offer of trading elections for the end of the embargo - a bid the White House makes in the certain knowledge it will not be taken up. No: it is to lift the embargo without conditions today, and make the real Fidel and Raul stand up. "The embargo has given the regime a cloak they can wrap around themselves. They can blame every abuse and every problem on it," Menocal says. Once it is gone, the hideous problems caused by suppressing all economic activity and all democratic sentiments will be exposed without excuses.

Shorn of the embargo-excuse, Raul would have to either open up a democratic space, fall back on the "cannons" he threatened to use against pro-democracy protestors in 1994, or fall altogether. It's unlikely the regime will pass peacefully into the night: Raul was the most enthusiastic chief of the Cuban firing squads in the early years of the revolution and the most vehement Stalinist in the years of Soviet slush-funds. Raul will probably try to pursue the Chinese route of loosening control of the economy while keeping fierce control of politics. But as the rap groups and liberal exiles show, Cubans are hungry to return to the democratic values articulated on the Sierra Maestra all those years ago, before Fidel became intoxicated by communism and raw power. They will not settle for becoming a new Shanghai.

But for now, it seems that even as Fidel fades, the American embargo and Cuban communism are determined to continue marching hand-in-hand into history, as slouching, slumping Siamese twins.

j.hari@independent.co.uk