For Rodrigo Sanchez and Gabriela Quintero, the road to Billboard's world music album chart started in their hometown of Mexico City, where the self-described metalheads were rejected from conservatory

For Rodrigo Sanchez and Gabriela Quintero, the road to Billboard's world music album chart started in their hometown of Mexico City, where the self-described metalheads were rejected from conservatory as teenagers.

After toiling fruitlessly together in a thrash band for years, the couple traded in their gear for a pair of Spanish guitars and decamped to the resort city of Ixtapa, where they hoped to save up enough money for a trip to Europe.

It was while playing Slayer and Metallica covers for unsuspecting tourists that their signature sound was formed. "We didn't have any proper background music for restaurants. We had to play all the metal stuff on acoustic guitars," says Sanchez.

In 1999, the two arrived in Dublin without a place to stay, and found themselves playing guitar on the streets and getting hassled by police. Undeterred, Sanchez and Quintero kept up their busking idyll in Copenhagen and Barcelona, until Damien Rice, once a fellow street musician in Dublin, invited them to play at his shows.

"We said, 'This could be a little more comfortable than playing in the streets,'" recalls Sanchez.

The two were eventually signed to an Irish label, and convinced the company to send them back to Ixtapa to record an album. "[But] we didn't record anything. We spent the time drinking and having a laugh with our Irish friends," admits Sanchez. (Production credits on the album include Negro Modelo beer).

To rescue the project, the label reached out to producer John Leckie (Radiohead, My Morning Jacket) to record what would eventually become Sanchez and Quintero's debut on ATO Records. In its fourth week on Billboard's Top World Albums chart, "Rodrigo y Gabriela" holds its third-place position, with sales up 30% from the previous week. The album has sold 5,000 copies in the United States since its Oct. 3 release, according to Nielsen SoundScan.

Listening to "Rodrigo y Gabriela," it's hard to believe that the only two instruments on it (with the exception of one violin solo by gypsy virtuoso Roby Lakatos) are the pair's acoustic guitars. Watching them play, it makes more sense; Gabriela's hands are a blur of speed over the strings, when she's not tapping out percussion on the guitar's body. Rodrigo's precise picking whips out a sound that swings unpredictably from infinitesimally small and high-pitched to a big bellow.

The two reject the flamenco label, drawing more influences from classic rock. The album features interpretations of Led Zeppelin's "Stairway to Heaven" and Metallica's "Orion" in addition to original musical tributes to the people and places they encountered during their trip around the world.

Sanchez says the group's touring commitments, which include a performance at the 2007 edition of the Coachella Valley Music & Arts festival, make it unlikely they'll return to Mexico anytime soon. Stateside, the two played 14 dates in October on a tour that took them to the West Coast, the famed Lotus Festival in Bloomington, Ind., and public radio's Mountain Stage in West Virginia. The tour continues in Europe and Australia.

For his part, Sanchez doesn't regret never having formally learned to read or write music all those years ago in Mexico City. "You have no rules to follow, and you develop a way to create different sounds," he says. "We didn't get into that classical training, and I'm happy now [that] we didn't."