How do you strike a chord with your country, culture or generation? Manu Chao, the Franco-Spanish singer-songwriter, thought his 1998 album Clandestino was going to flop - instead it went on to sell more than five million copies.
The reason? It struck a chord with a generation of young people who grew up in a world of globalisation and international travel.
He became a poster boy of the anti-G8 concerts that mushroomed around the world, as young people protested at the way wealthy, developed countries were imposing their will on others.
"What Clandestino is talking about is problems of borders, and more and more hermetic borders all around the world," Manu Chao told the BBC World Service.
"Immigration of people has been important for the story of this planet, to make what is today...
"Imagine thousands and thousands of years ago, when the human race was born in Africa, if we'd not allowed them to get out of Africa then we wouldn't exist," he says.
Serious subjects for what sounds at first listening like a light, fun record - but that seems to be part of the secret of striking a chord with a nation or generation.
The songs that pull it off touch, in many cases, on universal themes which resonate with millions of people - whether it's immigration, love, loss, pain or revolution.
Manu Chao didn't intend his album as a political statement, but it quickly became one.
If you listen to Clandestino's title track, Latin-infused reggae sounds and chirpy street recordings from Mexico contrast with the pain, confusion and fear that Manu transmits about the experience of immigration (one of the meanings of "clandestino" is "illegal immigrant").
Fear and sadness
Some of this comes from his own background - his parents were political refugees, who escaped Franco's Spain to move to France.
The realities of the 1990s, when waves of illegal immigrants found their way to Europe, and where millions were living sans papiers (without papers) and in fear of police checks and round-ups, struck a chord with Manu himself.
"It's stupid, just because I was born with a French passport, I have the right to travel all around the world, but if I was born in Mali, or Venezuela or Bolivia I couldn't. That's just crazy," he says.
"It's a kind of suicide to close the borders... Europe is ageing, it needs the youth, and the youth come from the third world."
After a number of successful albums and tours around Latin America with his band Manu Negra in the 1990s, he travelled back to Mexico and Brazil and started recording street sounds and music on a hand-held recorder.
Those sounds, his nomadic existence, coupled with the experiences of his immigrant friends in Paris and Barcelona inspired the album.
He never wanted to glamorise his experiences or those of his friends. He says there is nothing romantic about being a clandestino, it's just fear, paranoia and sadness.
He was convinced it would be the last album he ever made, as no-one would like it, but gradually the album's success grew and grew.
Passed from traveller to traveller as they journeyed around the world, it was almost as though the album itself was clandestino, he says.
"Now the album has become a kind of anthem for clandestinos all around the world," Manu says. "And for that I'm proud."