When this reporter was assigned to review Los Lobos at the Napa Valley Opera House Saturday night, the unofficial word was it would be acoustic instruments only. Poor old wolves, I thought, reduced to playing lullaby music, watered-down versions of the old rowdy rock-blues-Tex/Mex mixture that is uniquely theirs.

Wrong.

In fact nothing was further from the truth. True, they took the stage with acoustic/electric instruments, including a guitarron, a Mexican bass that looks just like an oversized guitar, but everybody was plugged in. That’s just as it should be for a band that got fired a lot in its early days for being too loud.

And it was a good thing they were amped, because it was a rowdy, sold-out house that was ready to howl.

The members of Los Lobos lives in two worlds: traditional Mexican music and the potpourri of American folk and popular music. That they can stride those worlds, move between them and, indeed, combine them into one almost seamlessly, speaks volumes for their skill as musical artists.

They played two 45-minute sets to a sold out house. By the time the night was over, everyone was on their feet and dancing in the aisles.

The first set was mostly from the band’s Latin oeuvre with the exception of “One Time, One Night.” It was stirring and enjoyable, and even though the audience appeared to be middle-aged Anglos, and presumable clueless as to the lyrics, shouts and rabid applause followed every number.

The second set began with the band’s first top 40 hit, “Will the Wolf Survive?” followed by “Hold On” from the 2006 release “The Town and the City.” The rockers were out in force during this set and the band played “Dream in Blue” (from 1992’s “Kiko” album) by shouted out request. No doubt the hardcore partiers also enjoyed “I Got Loaded.”

It’s hard to imagine a tighter band than Los Lobos, which is all the more amazing given their blend of instruments and cultural influences. How many bands feature a baritone saxophone on a flamenco-sounding tune?

They ended the second set and ostensibly the evening with “Guatanamera.” Most old gringos (yours truly) remember the song from the top 40 hit version done by the Sandpipers, a quasi-folk-rock group from the ’60s with “easy listening” tattooed all over it.

However, the title means “girl from Guantanamo,” a rather topical place these days, and Latinos know it as the most famous Cuban patriotic song. Make of that what you will.  

As an encore the band played a song, live for the first time, from a children’s project they are working on for Disney.  

The way the crowd was dancing and applauding they could have gone on all night.

As Opera House Evy Warshawski said while introducing the band: “They are known as trailblazers and mavericks, noted for always moving in the opposite direction of their last album.”

I hear that. The Wolves not only survived, they thrived.