Musicians Rodrigo y Gabriela play the Warner Theatre Wednesday. (David Moulin/David Moulin)

Part of the appeal of Rodrigo y Gabriela, the duo who furiously combine flamenco and metal shredding on acoustic guitars, is that all their fury is created by just two people.

So fans may be understandably taken aback when the two walk onstage for their current tour with six other musicians.

Even as Rodrigo y Gabriela play some of their best-known songs Wednesday at the Warner Theatre, they will come with different rhythms and even different soloists.

“Some of the fans are surprised,” Rodrigo Sanchez says from Los Angeles, the day after a lively performance on “The Tonight Show with Jay Leno.” “But as the show goes along, they understand.”

Some in the audience may be relieved when the additional musicians performing under the name C.U.B.A. (Collective Universal Band Association) clear for the second half of the show, leaving the duo fans have come to love.

By the time the musicians rejoin them for the show’s conclusion with the remaining songs from their latest album “Area 52,’’ the fans are fully on board.

The augmented duo represents for Sanchez and Gabriela Quintero, both 38, a return to their original form, a band.

When the longtime couple, who are not married, gave up on their hometown Mexico City metal band and moved to Ireland in 1999, they performed on the streets.

With Quintero beating a thumping percussion on her guitar and Sanchez soaring with an intricate melody line, they kept their heads down and played three different speeds, according to one early reviewer: “fast, very fast and super fast.”

Crowds grew, record companies called and suddenly Rodrigo y Gabriela were signed to an Irish label and playing big European festivals, quickly gaining a global audience and selling more than 1 million albums.

Though they’re depicted in their most famous music video in front of huge stacks of speakers, they produced their power on the nylon strings on acoustic guitars, breathing new life into songs inspired by classic rock or sometimes, specific tunes from bands such as Led Zeppelin, Pink Floyd and Metallica.

Back with a band, and all the communication and musical exchange that represents, Sanchez says, “We feel way more relaxed; we feel we’re sharing responsibilities onstage after so many years of being on our own.” The two have enjoyed playing as a duo, too, he adds, but increasingly there has been “a certain amount of pressure on us, especially in recent years.”

In addition, “it feels good to introduce these amazing musicians to the audience.”

A wildly varied roster of musicians appear on “Area 52,” which was recorded in Havana and released in January. It included Los Van Van drummer Samuel Formell, sitarist Anoushka Shankar; Palestinian oud players Le Trio Joubran; bassist Carles Benavent, who has played with Paco De Lucia, Chick Corea and Miles Davis; and drummer John Tempsta who has backed metal groups from Testament to White Zombie.

Another addition to the multinational sessions was producer Peter Asher, a onetime duo member himself in Peter and Gordon, who previously produced James Taylor and Linda Ronstadt.

But the only holdover from the album’s personnel on tour is Alex Wilson, the London-based jazz pianist who arranged many of the Rodrigo y Gabriela songs reworked on disc.

Sanchez says he conceived of the Cuban album as a way to bide time before the next studio recording. They had already released three live albums — here was a chance to use their previous compositions from “11:11” to “Tamacun” one more time with a new sound.

“I thought it was going to be simpler,” he says. Just get the tracks, give them to a Cuban musician and let him add the rhythm — “like a backing track band, you know. But it wasn’t like that at all.”

Instead, “it became like more a project where we reinvented the songs in a way; it was not even like arrangements. Because what Alex Wilson did was to propose different rhythms for each song, and there are so many different Cuban rhythms, and then once we agreed on that, Alex Wilson, Gabriela and myself, we got together and then together we restructured each song.’’

At the same time, it meant sharing a lot of the parts they did so furiously themselves.

“Gab had to sit with the drummer and with the percussionist at the recording and for the live shows for a few days beforehand so they understand each other,” Sanchez says. “Obviously, Gab knew she was going to let go of some of the responsibility of carrying the whole percussion element, but it’s the nature of project.”

“In general, Gab is very, very happy, because she’s learned a lot of rhythms that she didn’t’ know,” he says. “And that was actually one of the reasons we decided to go to Cuba as well: we knew we were going to learn a lot from these musicians. And it’s been a full-on intensive course on rhythms and a musical language that we’ve never taken before.”

It also gives Quintero’s hand a break — the duo had to stop touring in 2010 because the furious percussive style had caused stress injuries to her hand.

“There it is a little more of a rest for both of us,” Sanchez says. “And that is absolutely necessary sometimes for us.”

Despite getting back in a band, he says the next studio album will be “the two of us only,” and “we’re going back to the rock, not even to the very Latin core things we did on the first album, but even more based on the rock feel that we have.

“I think we have to move on in terms of what we’re first well known for — acoustic music based on Latin rhythms and rock. But we don’t want to repeat the same things.”

So far, Rodrigo y Gabriela have been able to attract audiences because they have avoided strict categorization: It’s not strictly flamenco, not strictly rock, and the fact it has never had vocals may have made it more exportable than other Mexican rock.

“It’s not like we do it on purpose,” Sanchez says of the genre-jumping. “We just don’t have any particular limits to what we want to do.

“I have a lot of friends that have gone into rock bands. For them it’s very difficult because they have different ideas to go with another genre of the music than what they play, but if they did that, they’d lose credibility. Which is stupid, but that’s the way it is.

“That’s how it works when you’ve been labeled strictly to one particular kind of music. So we’re happy not to be part of that and we find strength to experiment as much as we want. And I’m glad from Day One we came up with something that is not easy to label; that opened a different road for us. And that’s how we want to continue.”

Catlin is a freelance writer.

Rodrigo y Gabriela, with C.U.B.A.

Wednesday at 8 p.m. Warner Theatre, 513 13th St. NW,, 202-783-4000.