As dynamic duos go, Mexican guitarists Rodrigo Sanchez and Gabriela Quintero (known to fans as Rodrigo y Gabriela, or sometimes just "Rod and Gab") might be considered the Batman and Robin of the acoustic music world, thrilling millions with their dexterous exploits safe for family friendly consumption.

But there was a time not so long ago when the pair were closer to Ozzy and Sharon than Ozzie and Harriet, although they've always just been good friends and never romantic partners. In the Mexico City "community of rockers," they met in the Casa De Cultura run by Rodrigo's brother. They were teenage metalheads — Gabriela had been in three all-female bands before joining Rodrigo in thrashers Tierra Acida (Acid Earth) — practicing like fiends up to five hours a day while working day jobs and playing clubs at night, which weren't very welcoming, according to Mr. Sanchez.

"Metal is very big for international bands like Metallica, who can play stadiums there. But for the locals, it's not very big. There aren't many known metal bands."

Although Tierra Acida recorded an album, the group never signed a record contract, and the pair tired of the routine. On a tip from a friend, they landed in Dublin and earned their living busking on the streets, from the boulevards of sunny Barcelona (where clubs assumed they were a mariachi act) to the freezing climes of Copenhagen. A support slot offer from Irish singer-songwriter Damien Rice (once a fellow busker) brought them the attention to release the "Re-Foc" and "Live in Manchester and Dublin" albums, which propelled them onto the circuit of world music festivals.

"We were in the world music scene for one summer," recalls Mr. Sanchez. "That was good, but then we didn't go back to it and fell into the rock thing," since performing at Glastonbury, Coachella and Bonnaroo, as well as the Fuji rock fest in Japan.

Launching them to that level was the self-titled 2006 breakout that hit No. 1 on the Irish charts and has since racked up more than 600,000 in worldwide sales. The CD was produced by John Leckie (Radiohead, My Morning Jacket) and featured seven originals as well as epic reinterpretations of Metallica's "Orion" and Led Zeppelin's "Stairway to Heaven," in case anyone mistook them for flamenco artists. To complicate matters, their new album, "11:11," contains the track "Master Maqui," dedicated to Spanish master guitarist Paco De Lucia.

"There's a little bit of confusion," admits Mr. Sanchez. "We love flamenco but never studied it — in fact, we were rejected from the traditional conservatory of music in Mexico. Although there is a similarity because of the sound of the guitar, the percussive technique Gab uses is from an instrument in Ireland called the bodhran."

He adds that the duo's rhythmic sound emerged from compensating for the loss of the bass and drums after leaving the Mexican rock scene. There's a clear division of labor.

"Gab became the drummer and bassist, and I stick to the guitar and melodies. But she's not in the back like a normal rhythm guitar — we get thumping, deep bass sounds out of the pickups we use and guitars that have been built specially for us. It's a heavy and loud sound, not like the classical training that people think we come from but totally with a rock kind of vibe."

Although the duo's music from "11:11″ on Irish indie label Rubyworks was featured on "Monday Night Football" for last October's Latino Heritage Month, the group doesn't specifically cater to Latin audiences.

"Although we are proudly Mexican, we don't belong to that genre. The second track on the album, 'Buster Voodoo' [dedicated to Jimi Hendrix], has been played on K-Rock in Los Angeles. We get support from Triple-A [Adult Alternative] stations. It wasn't our intention to do an instrumental rock-based acoustic thing. It just came out by accident, and the media responded to that. When we played on TV, [David] Letterman told us we were only the second instrumental group to play his show."

"11:11," its title alluding to the New Age concept of synchronicity (the accompanying interview video in the album package is adorned with Mayan numbers and glyphs), is a tribute to various iconic influences the duo has felt in its career and not a specific religious quest.

"We do read about different spiritual views and journeys, but we don't want to tell people what to believe. The track names are related to specific artists — for example 'Hanuman' is dedicated to Carlos Santana, who was into Hinduism in the '70s and later became Christian. 'Savitri' is dedicated to John McLaughlin."

Other songs (all fairly short and radio-friendly instrumental flights of fancy) list dedications to lesser-known artists. "Triveni" namechecks Trio Joubran, three Palestinian brothers who live in France and are masters of the oud. Meanwhile, "Chac Mool" is linked to Mexican composer Jorge Reyes. (An ambient electronic wizard on the same level as Steve Roach and Robert Rich, he died last year at the age of 57.)

The album's guest stars might attract a few more listeners. Acoustic guitar duo Strunz & Farah, who've been around since the early '80s stirrings of the New Age scene, are featured on "Master Maqui," while one of Mr. Sanchez's all-time heroes — guitarist Alex Skolnick of metal band Testament — is on "Atman," dedicated to deceased Pantera axe-king "Dimebag" Darrell Abbott.

Mr. Skolnick's electric jazz trio, which includes Pittsburghers Nate Peck on bass and Matt Zebroski on drums, are opening a string of theater dates for the duo in the States, including Tuesday's stop at the Byham Theater.

"When the first album came out, [Mr. Skolnick] sent us a message on MySpace," recalls Mr. Sanchez. "We were huge fans of Testament and couldn't believe it. We asked him if he wanted to come to the show and play with us, and he immediately said yes. Since then, we have become very good friends, and I'm glad he's doing this tour."

Mr. Skolnick may have partly inspired the former metal maniacs to rise from their seats and work the crowd more.

"When we first toured the world, we were just sitting there on chairs," says Mr. Sanchez. "But then we changed the concept of the show. We stand all the time and run around on stage. We have a new stage show designed by Paul Normandale, who worked for Bjork. He made the designs simple because we're not a pop band, and we don't want to overdo it. But we have camera shots [of our playing] and visual images from Alex Gray and Spanish painter Remedios Varo, who came to Mexico when she was young and did a lot of her best work there."

Rodrigo y Gabriela also returned to Mexico and now reside in the peaceful beach resort town of Ixtapa on the south Pacific coast, where they built a home studio and recorded "11:11." They advocate for "green" causes such as the wildlife preserve El Refugio De Potosi, which promotes conservation and eco-tourism in the Zihuatanejo region. The "B Major Sessions" video blog on their site ( inserts environmental messages (some a bit preachy about veganism) while sharing music recorded in the dressing room.

"We have friends who guest in the videos. The idea is to share some environmental awareness that is relevant to the lifestyle we live every day. We just decided to do it with music."

But because the duo get blogged about on sites such as Metal Martyrs and "11:11″ was produced by Colin Richardson (Slipknot, Trivium), no one should be surprised to see long-haired dudes in the audience who refuse to give up hamburgers and hot dogs.

"We have [metal fans], but we're not a metal band, so it's interesting. Some journalist in Japan called us one of the few artists who could play onstage with both Al DiMeola [to whom they pay tribute on the track 'Logos'] and [Metallica bassist] Robert Trujillo."

Which they did.

"The last time we played in Chicago, Robert came to our show and wanted to jam with us, and it was great. Heavy metal and jazz fusion are not as far away from each other as people think. A lot of people dismiss metal because of the way it's presented or because it's too loud or distorted, but there is something behind all that — to be in a good metal band, you have to be a great musician."

In comparison, Mr. Sanchez isn't that impressed with the popularity of indie rockers who have risen to a commercial level of appeal.

"They don't need to play that well to write some songs and win a Grammy. I would always rather support a metal band that's willing to play well than other kinds of genres."

Manny Theiner is a Pittsburgh-based freelance writer.