That was five years and three albums ago, and Mariza has quickly become not just the new face of fado but also the impetus behind its miraculous reinvention as cool, which was no small task. Portugal's Estado Novo, the authoritarian military regime that ruled the country for an astonishing 41 years, controlled the airwaves during its reign, and fado was endorsed and encouraged. Needless to say, music forced down the throats of a resentful population can't possibly be considered hip.

"During the regime, we only had one television station, and they treated fado very poorly," she explains. "So the younger intellectuals and more sophisticated audiences would see it and say, 'This is not my style.' It was too connected with the regime, and people harbored those memories."

As a result, anyone born in the late '60s or after considered fado the music of their parents - a deathblow in any culture. But nowadays, when you step inside the Fnac record store in Lisbon's trendy Chiado district, you'll see Mariza's latest album, Concerto em Lisboa, in the top 10, alongside those by Madonna and Kelly Clarkson. She has sold more than a million records worldwide (an insane number for a world-music artist). In the same way that Nirvana chewed up and spit out rock music in the '90s, Mariza has jump-started fado.

Mariza counts performing with the Los Angeles Philharmonic in 2004 at the then newly opened Walt Disney Concert Hall in L.A. as one of the proudest moments in her life to date. (Currently on tour in the United States, she'll have the opportunity to perform there again at the end of this month, with award-winning architect Frank Gehry turning the stage into a cozy fado tavern just for her.) She's just as proud, though, of a fado megaconcert she gave in Lisbon in 2005. The recording of that concert is her latest release.

"If you invite someone from fado to do a concert in an open-air space in Lisbon, you don't [normally] get more than 5,000 people," she explains. "I asked the municipality to let me do a concert in the gardens of Belém. It was raining that day, and I was crying over it. I didn't think we would get anyone. When I entered the stage, there were 22,000 people [there]. It was the biggest fado concert ever in Portugal." Concerto em Lisboa chronicles that evening.

Like most Americans, I don't know fado from Play-Doh, so Mariza agrees to play tour guide for a day and teach me everything there is to know about her music, her city, and the fado clubs that are such an intrinsically significant part of life in Lisbon - and a major tourist attraction to boot. But which clubs are tourist traps, and which are the real deal? The country's biggest fadista should know, after all.

We fuel up for our journey at yet another hole-in-the-wall seafood spot, Churrasqueira do Sacramento, in the Alcântra neighborhood of Lisbon. It's packed with people clamoring for one of but a few tables in the place. They are used to Mariza here, so nobody bats an eyelash at her presence. And that's the way she prefers it. "It's very normal," she says. "That's why I like it." She fends off the manager's advances to take her coat for her and throws it around the back of her chair, just like everybody else in the restaurant has done.

When we finish our meal, we are within walking distance of the Museu do Fado, the fado museum. It's normally closed on Mondays, but they open up at the first sight of Mariza, who views the museum as the logical starting point for those interested in submersing themselves in Portugal's most beloved form of expression. Mariza's albums and awards are housed here (her 2003 BBC Radio World Music Award, for instance), alongside those of Amália and other big-name players like Carlos do Carmo, yet she breezes right by them in favor of showing me a three-dimensional painting called Viela (Alley), Rua Pimentel 1998, a reconstruction of what a typical Lisbon neighborhood looked like hundreds of years ago. That's when I hear my first few notes.

"Sardinhas vive!" she sings, describing how an old woman, such as one of those depicted in the painting, would shout out "Live sardines!" to let the neighborhood know what she was selling. It is surely the most beautiful touting of a small salty fish that I've ever heard.

Later that evening, our first stop is, naturally, Senhor Vinho, the fado club where Mariza got her start. She is welcomed with open arms - though the up-and-coming fadistas on tonight's bill must surely have started shaking in their boots when she came through the door. In America, the equivalent would be Shania Twain walking into a small country bar in Nashville on an open-mike night.
The first singer is Filipa Cardoso, a traditional fadista who has more in common with Amália than with Mariza. Then, the moment she begins to sing, a startling thing happens: Though dinner is being served, all knives and forks drop, all conversations cease, and all drink orders are put on hold - the room becomes as silent as a prayer session at the Vatican. Of all the things I've ever seen in Lisbon, it's this show of respect that I will always find most endearing.

Despite chants of "Ma-ri-za! Ma-ri-za!" from a table of drunk Spaniards, Mariza does not get up and sing. Instead, we move on to A Tasca do Chico in the Bairro Alto, Lisbon's nightlife hub and the home to many fado clubs, all of which pale in comparison to this one. Unlike most fado venues, A Tasca do Chico is a dive. The walls are covered in soccer banners, and the place is spilling over with people from all walks of life. Locals love it because anyone can sing fado here - it's a free-for-all - and Mariza loves it for the same reason. It's not uncommon for taxi drivers to roll in, sing a few fados, then get right back into their cabs and speed off into the night. We pile into the old-school wooden picnic tables and join a family as if this sort of thing happens every day.

If Mariza's presence can make the professionals nervous, imagine how the amateurs feel when she's around. One woman in her mid-30s starts her fado but soon chokes up. She apologizes and quickly loses herself back in the crowd, claiming nervousness. Another forgets the lyrics; another sings completely out of tune.

Partly due to the raucous nature of the club, partly due to Mariza's visit, the place is so loud that you can hardly hear yourself think. People are turned away, as the club is at capacity (and probably then some). The MC lays down the law: "No silence, no fado," he says. "You choose." (There are no mikes in fado.) The crowd settles down for Artur Batalha, a formerly successful fadista whose career was on the up-and-up in the '80s but who later fell victim to the vices of fame. His voice still has the goods, though.

Before he sings, he looks at Mariza; the two of them hail from the same working-class Lisbon neighborhood. "It's a pleasure to see an artist in person whom I love." He calls her a daughter. Mariza sings along to his fados under her breath.

The night is winding down, but the crowd wants more. They want Mariza. The MC once again hushes the crowd. "So you will go home in peace," he says, "Mariza!" She calmly slides out from the table to the roar of the crowd, briefly consults with the guitarists, and seconds later, without so much as a single moment of warm-up, she launches into "Quando Me Sinto Só" ("When I Feel Alone"), from her last studio album, Transparente.

Her voice soars and captivates, radiating through the roughened walls with piercing delicacy. The room is frozen. Though nobody has much space to do so, they give her a standing ovation. Batalha, sitting nearby, bows his head, covers his eyes, and holds his hand over his heart. In peace he goes, as do we all.

American Airlines serves Lisbon via London, with service operated by oneworld partner British Airways.