El Teatro Karl Marx is known to all Cubans as the impressively ugly 1960s monument to communism where Fidel Castro delivers his lengthy speeches exhorting the glories of the revolution.
This evening, the adoring masses will again gather in central Havana to hear radical firebrands preach the gospel of anti-Americanism. Only this time, the performers are the Manic Street Preachers.
Yards from the Plaza de la Revolucion, where Che Guevara is immortalised in a 70ft steel frieze, three men from Gwent will bring Welsh pop to the land of salsa.
Quite what an audience brought up on the gentle rhythms of son music, popularised by the Buena Vista Social Club, make of the Manics' brand of high-octane Celtic rock will become clear in the early hours of tomorrow.
The performance has already been heralded as proof of Cuba's reintegration into the international mainstream in defiance of the 40-year-old economic and cultural blockade by America.
The appearance of "Los Manicos" on the tattered bill of attractions in the 5,000-seater Karl Marx auditorium is the first in Cuba by a big Western name since Billy Joel defied his nation's embargo in 1971.
For the Manics, the gig is a chance to celebrate Cuba and stick up two fingers at the US. Nicky Wire, the bassist, said on arrival in the faded grandeur of old Havana last night: "We've got a lot of respect for the Cuban people and the Cuban culture. We wanted to do something different.
"This is not some student Che Guevara fixation thing. It is because Cuba is the last bastion that is holding out against the Americanisation of the world," Wire said.
The band is using its politically charged meeting with the land of rum and cigars - their first public performance for more than two years - to launch their sixth album, Know Your Enemy.
Billed by Martin Hall, the Manics' manager, as a "once in a lifetime" opportunity for ordinary Cubans to hear the songs before anyone else in the world, ticket prices were set at 25 cents (17p) for locals.
Yesterday, among the souvenir stalls in Vieja Habana selling mass-produced Guevara berets and T-shirts, word was spreading about the exotic rebels from a culture to which Cubans still have little access. There was a thirst among the country's youth, more accustomed to salsa and jazz, for a chance to hear a band whose recent song titles, including "Masses Against the Classes" and "Freedom of Speech Won't Feed My Children", could have been dreamt up by Castro himself.
One song on the new album, called "Baby Elian", will delight the Manics' hosts for highlighting last year's custody battle over six-year-old Elian Gonzalez, who survived a shipwreck in an attempt to flee to the United States. The chorus includes the words "Kidnapped to the promised land... America, the devil's playground".
One young Habano, Jojo, a bass player for the Cuban rock band Zeus, said: "I'm glad they're here and I hope lots more foreign bands will be following them." Such bands are rate in Cuba.
Cuba watchers say the event fits into a pattern of increasing exchange with the West now permitted by a regime that has succumbed to the lure of the dollar. Ever since the Soviet Union collapsed and stopped propping up the Cuban economy, tourists have filled the island's coffers with greenbacks. Cruise ships and charter aircraft arrive with hundreds of visitors every week, most of them from Europe and Canada, with a scattering from the US in defiance of the blockade.
The reason they are to be found crowding along Havana's famous curving Malecon seafront, and in the streets among Cuba's patched-up 1950s Chevrolets and Buicks, is apparently because the island is the place to be seen.
The Labour MP George Galloway, and one of Britain's most ardent Cubanophiles, said: "All cultural roads now lead to Havana. Everyone wants a taste of Cuban cool. It is no surprise that a British pop band is among them."
In a gesture to prove it is not all one-way traffic, a statue of John Lennon was recently erected in Havana after Castro officially designated the former Beatle as Cuban communism's favourite pop revolutionary. The fact that within days thieves had stolen the musician's wire-rimmed spectacles from the statue, probably for sale on the burgeoning black market, was forgotten.
So far, so progressive. But the presence of the Manics and the atmosphere of togetherness that this weekend was supposed to generate was not all it seemed. Confusion reigned last night about the number of 25-cent tickets available to Havanans after the news that most of the audience, including British media and fans, will be there by invitation only.
And, while only a few Cubans will get to see the Manics in action, even fewer will have had the chance to hear about them. The official media, including Cuba's youth paper Juventud Rebelde, has given the Welshmen's arrival just one paragraph of coverage. Even then the brief article got the date of the concert wrong. Pop experts also pointed out that the anti- conspicuous consumption Manics can only profit from the widespread publicity generated by their transatlantic jaunt.
Jody Thompson of the music newspaper NME said: "There is obviously a financial aspect to this. They are launching their album there, but they will still be making money everywhere else."
Even more worrying for a quickly changing Cuba, and the Manics' aspiration of halting the ubiquity of the land of Mickey Mouse, however, was the fact they may be having the opposite effect.
Kids hanging out on the Malecon struggle for months to save up enough dollars to purchase fake Nike trainers or a Tommy Hilfiger knock-off.
Rather than soothing jazz, they usually prefer listening to the Back Street Boys or Eminem on a radio tuned to a station somewhere across the narrow Florida Straits. It becomes a small act of defiance.
Discos throb with the most anodyne pop songs and any tapes of rave or trance music have real cachet on the street.
After the 40-year embargo, Cuban youth is fed up with a lifetime of resistance and struggle, and cannot be blamed for snatching a little self-indulgence where they can find it. For all the Welshmen's protestations of high moral motivation, however, there were rumours last night that the trip to Cuba is no more than an elaborate smokescreen for a reunification.
Six years ago, the Manics' self-mutilating singer, Richey Edwards, disappeared without trace from the group's hotel in south-west London.
His empty car was found near the Severn Bridge - a notorious suicide spot - but no body was ever found and rumours persisted he may have gone into hiding at a series of exotic locations, including Cuba. The date when his car was found? 17 February.