Mars Volta pioneers a musical universe

During a technical-difficulties-induced break after the band Mars Volta’s first song at the Greek Theatre on Saturday, singer Cedric Bixler-Zavala quipped, “I think this is God’s way of telling us to write regular songs.”

Well, that first song, “Drunkship of Lanterns,” spanned more than 20 minutes, covered musical ground from free-jazz squonk to salsa-influenced jams to Zeppelin-hard rock -- often all at once -- and featured emotions colored in various shades of intense. So, God’s request is probably going to get ignored.

What cannot be ignored is that an audience for the Mars Volta is growing in variety and intensity. Seeing the diverse and mostly young sold-out crowd of 6,000 enthusiastically embrace the challenging, unconventional music was as exhilarating as the performance itself.

Formed out of the ashes of At the Drive-In by Bixler-Zavala and guitarist Omar Rodriguez-Lopez, the Los Angeles-based band has over the course of two albums developed a distinctive language. The recent “Frances the Mute,” inspired by an anonymous diary found by band member Jeremy Ward and by Ward’s subsequent overdose death, is both an imposing and involving artistic statement.

Live, the Mars Volta is continuing its explorations and evolutions -- in part, thanks to the ensemble the leaders have assembled. Bassist Juan Alderete de la Pena and drummer Jon Theodore form a rhythm section as muscular and supple as any. Keyboard player Ikey Owens and horn and flute player Adrian Terrazas offer a wide palette of colorations. And percussionist Marcel Rodriguez-Lopez and former At the Drive-In member Paul Hinojos-Gonzales, taking over Ward’s “sound manipulator” role, ensure elements unique for a rock band.

Collectively, they’re as versed in Tito Puente as in King Crimson, virtuosic but never at the expense of feeling.

In that latter regard, perhaps most notable Saturday were the moments of restraint. Somber stretches sometimes lasted just seconds, others much longer, as in the ballad “The Widow,” which recalled early Zeppelin as Bixler-Zavala soared like prime Robert Plant -- and was the closest to “regular” this group comes. These passages still bore an uneasy quality, but with an air of grace. And in “L’Via L’Viazquez,” a round robin of solos by Owens, guest guitarist John Frusciante of the Red Hot Chili Peppers, Omar Rodriguez-Lopez and Terrazas (on flute) was marked by open joy.

The tour de force was the closing “Cassandra Geminni,” the 30-minute climactic suite of the “Frances” album. Sweeping and transfixing, unpredictable and engaging, it manifested the slogan emblazoned on Theodore’s kick drum as an artistic credo: “Liberte ou la Morte” (Freedom or Death).