Hundreds of thousands of Cubans were expected Friday at the Rolling Stones' first gig on the communist island, with fans once banned from listening to rock 'n roll heralding a dream come true.
The four superstars led by Mick Jagger flew in late Thursday for the free-of-charge concert at Havana's Ciudad Deportivo sports centre.
Cuban state media forecasted that about 500,000 people were to fill the playing fields, with music industry magazine Billboard reporting that as many people again could swarm into neighbouring streets.
With no tickets on sale, it was impossible to confirm the estimates, but a million fans would amount to one of every 11 Cubans.
The concert — a surprise addition at the end of the Rolling Stones' Latin America tour — was to be the first by such a big group in Cuba.
Coming three days after a groundbreaking visit to Havana by US President Barack Obama, the event was widely seen as another step in Cuba's emergence from years of cultural, ideological and economic isolation.
The one party state, run by the Castro brothers for more than half a century, long looked down on British and US rock as subversive.
Between the 1960s and 1990s, rock 'n roll was discouraged to varying degrees, leading during the most repressive years to clandestine listening sessions and an underground trade in smuggled records and cassettes.
"A Rolling Stones concert in Havana? It's a dream," said Eddie Escobar, 45, who founded one of Havana's few clubs for live rock music, the Yellow Submarine.
He remembers secretly searching for US commercial radio frequencies so that he could hear the Stones, Led Zeppelin, Deep Purple and the like.
"Rock music, I hope, will open everything else — politics, the economy, the Internet. We're 20 years behind absolutely everything," Escobar said.
There were no concert posters around Havana as late as Thursday and the only merchandising AFP reporters found were key rings with the band's tongue logo in a state-run music shop.
Official stores still refuse to stock foreign rock. So to get a Stones' album, Cubans — who have little Internet access and cannot shop online — must go to shops selling pirated CDs.
If ideology was once the reason that foreign rock 'n roll was so rare, today the barriers are mostly logistical and financial, with few major groups taking on the challenge — and none with the stature of the Rolling Stones.
In a country where local rock bands have trouble finding even basic equipment like electric guitars and amplifiers, the Rolling Stones had to start from scratch.
Organisers told Billboard that the stadium-level production meant importing gear in 61 sea containers and a packed Boeing 747.
Even if few Cubans see Twitter, the band called on fans to vote via tweets for one of four songs — "Get off my cloud," "All down the line," "She's so cold," and "You got me rocking" — to be included on the playlist.
One Cuban fan, who gave his name as Rocky, took no chances, planning to sleep out in the sports park overnight.
"I have the impression that it's the start of a new era where the country will open up a bit to other countries' culture and influence," Rocky said.
And while other groups have played gigs, this is different.
"These are the Rolling Stones!," Rocky said.