The tangerine sunlight, deepening and sweetening as dusk approaches, strokes the peeling stucco of Havana's colonial ruins, every doorway teeming with life, every window framing faces and pouring out music.
But what everyone knows - every leather-skinned believer in the revolution, every velvet-skinned chica strutting her stuff, every vested old man slapping dominoes onto a fluorescent-lit table - is that the sun is setting on more than just another day.
They know that as Cuba prepares for the 50th anniversary of Fidel Castro's proclamation of revolutionary victory next January 2nd the fortress island is on the brink of something new, or least the end of something old.
What kind of change that will be is as unpredictable as Cuba itself.
The more President George Bush denounces Cuba, as he did last month calling it a 'tropical gulag', the more the Communists heave another breath of life.
Nothing unites Cubans behind Castro and his brother Raul - currently and 'temporarily' at the helm - more than a sense of righteous isolation and defiance of the bully across the straits.
Hoardings proclaim that 'To Threats and Intimidation, Cuba Responds: MAS REVOLUCION!' - More Revolution.
But after 50 years, revolution is a strange business. Last week the streets of Havana were crammed with trucks loading and unloading fridges.
The government had decided it is no longer tolerable for people to have to put up with vintage American and Soviet refrigerators and replaced them free with new Chinese ones.
But just as Soviet blocks along the white sands seem incongruous - a sort of Leningrad del Mar - so does the notion of a Chinese model.
There is a consensus among both the government and its opponents that whatever happens next should be in some way Cuban.
Part of the dichotomy on which Cuba exists is the tension between ideological austerity and vital sensuality, Marxism and deeply-rooted, potent spirituality.
Some things will not change. The drums will keep drumming in apartments like that of Miriam Fuerte, where the Santeria dance of the walking dead proceeds beside an altar made up of objects including the Madonna of Guadeloupe and a model Soviet bomber.
Wilfredo Morales Lezca, 27, a loyal communist and successful candidate to the provincial assembly elections last week, is a teacher of calculus mathematics. He said: "You may be surprised to learn that the communist movement in Cuba is quite young, although it's hard to convince the generation which watches Friends on television and has this fantasy that capitalism means money and that lifestyle for everyone."
"They have no idea of the sacrifices and hard work which have gone into what they have, like a good education and health service. We can now integrate Cuba into the new Latin America, trading our strengths for those of others, as friends and neighbours."
But second-guessing the future of Cuban communism is not easy. The veteran Cuban journalist Angel Tomas Gonzalez says the key to change is the army.
"Fidel's problem," says Tomas, "is that he genuinely dislikes money. He was educated by Jesuits and remains an atheist Jesuit wearing fatigues instead of the frock. That's why there was no problem between him and Pope John Paul."
"The army, on the other hand, is reformist. It has no problem with money. For a while, the army has run its own commercial enterprises with some success. In some ways, the change everyone is waiting for has already happened."
To presume that Cuba changed is Cuba reformed is an illusion. Quite apart from the bellicose Cuban-American right wing in Florida there exists a less shrill opposition within Cuba.
Arriving in Cuba five years ago, I made for the doyen of the opposition, Elizardo Sanchez. But Sanchez conceded he was no longer the driving force and directed us to the home, in the dilapidated colonial barrio of Cerro, of an electrician called Oswaldo Paya. Despite persistent harassment, Paya was organising a petition for the upholding of specific democratic clauses in the Cuban constitution. It was called Proyecto Varela, after a Cuban nationalist democrat.
Paya is still in Cerro, his greeting warm but his manner hunted and haunted, fastening the door to talk lest our conversation be interrupted by the local CDR or political police, Castro's KGB.
The signatures for democracy were duly delivered, and on Paya's wall is a photograph of the moment. Many were arrested soon after the delivery, and others during the "Black Spring" of 2003 timed to coinside with the invasion of Iraq.
Just as Sanchez led us to Paya, Paya's allies now recognise another, younger force. Generation Y is an internet site run by 32-year-old Yoani Sanchez.
"We're a kind of erratic, digital, political Rumba," Yoani said. "We're not encouraging people to be dazzled by savage consumer capitalism like they were in Eastern Europe."
The problem with Yoani's project is that most Cubans have no access to the internet. It also emerges that among Ms Sanchez's inspirations is a name I know well.
Nearly 15 years ago, I encountered the remarkable Eloy Gutierrez-Menoyo in Miami. He had been a commander on the revolution's Escambray Front but, appalled by what he saw as its betrayal to the USSR, mounted what he called "revolution against the revolution" for which he was jailed for 22 years.
He passed seven of those years in solitary confinement playing chess against himself in his head and composing poetry, later set to music by Cuba's great singer, Albita Rodriguez.
When he was released and defected to Florida, Gutierrez-Menoyo established a movement, Cambio Cubano, to campaign for peaceful change. He stood against the US embargo and for dialogue with Havana, for which his offices were firebombed by Cuban-Americans. He joked: "If the communists jail me and the right wing want to kill me, I must be doing something right!" and promised in 1998 that our next meeting would be in Havana. "Impossible," I replied. "So you were wrong," jokes Gutierrez-Menoyo in his Havana apartment. "But not entirely - in theory I don't exist in Cuba. I have no identity card, and no right to a home. But they couldn't stop me coming back. I am engaged in activismo. For democracy, free unions and a free press".
Gutierrez-Menoyo criticises some of the other dissidents for being too close to the United States. He said: "I fought one revolution which was betrayed to the Soviets and I don't want another for the sake of the USA."
In her flat above the Havana skyline, Julita Nunez Pacheco stares at a picture of her husband, Adolfo, staring back from a button reading "Prisoner of Conscience," as Amnesty International declared him and 74 others arrested suddenly.
"In Cuba," says Julita, "You see open people, open faces, doors and windows. But inside every Cuban is their own policeman, only the policeman is getting weaker."