Your sacred cows mean nothing.

That, at least briefly, was the message of Los Campesinos! last night at a packed 9:30 Club. “I never cared about Ian MacKaye,” sputtered Gareth Campesinos!, the Cardiff, Wales-based group‘s frontman, in “The International Tweexcore Underground,” surely aware of the lyric’s particular application. Not that the audience — whose average age couldn’t have exceeded 18 — noticed or cared. Throughout the evening it returned the septet’s considerable panache in triplicate, pogoing and mouthing along to each sarcastic word, even when the group’s schoolyard accents and entropic arrangements swallowed the vocals whole. Energy overpowered attitude, and for a while, that was fine.

Though the group played many of its “rubbish older songs” — as Gareth referred to numbers still less than three years old — the members are clearly starting to get over the knowing cocksureness of their early recordings. “I’ve got so many witty retorts,” Gareth proclaimed at one point, but refrained from dispensing them because, he said, his hecklers were unamplified (for Los Campesinos!, context is everything).

The band has released two well-received albums since its 2007 EP, Sticking Fingers Into Sockets, carefully honing its dichotomous sound — which pits thick guitars and distorted bass against whispy strings and gurgling synths — along the way. But the lyrics are another matter. Once Los Campesinos! sang about bands you surely know and mixtapes and the absurdities of twee culture, reveling in the blend of irony and insiderness with which young lyricists often mask a lack of confidence. Coupled with Gareth and Aleks Campesinos!’ bratty inflections, it was really, really annoying stuff. I miss it dearly.

The less immature Los Campesinos! (I hesitate to say “more mature”) concern themselves with matters of the heart rather than the mechanics of hipster cachet. In “We Are Beautiful, We Are Doomed,” Gareth sang “I taught myself the only way to vaguely get along in love / is to like the other slightly less than you get in return / I keep feeling like I’m being undercut,” which on paper is a much more satisfying lyric than “Sarah Records never meant anything to me / but the International Tweexcore Underground will save us all.” But twee pop is one of the few genres (along with hip-hop) that can thrive on self-reference, in its case the more cloying, the better (think Tullycraft). Which is to say: Los Campesinos! should be in no hurry to grow up. In this era of bromances and the elevated fart joke, they are our brat punk.

And for all their too-cool-for-schoolness, Los Campesinos! are clearly a band of fans: How else to account for a jagged cover of Pavement‘s “Box Elder,” or the unmistakeable influence of the U.K.’s post-C86 generation (particularly bands like Heavenly or The Pastels)? Likely, it was no accident that the two bands that opened — Chicago’s Smith Westerns and San Francisco’s much-buzzed Girls — fell just as easily into categories of record-collection rock.

For reasons too boring to explain, I missed most of Smith Westerns‘ set, but what I did hear reminded me more of, say, T. Rex than the  Vivian Girls or Crystal Stilts vibe I get from their very lo-fi album. And Girls, who didn’t do much for the crowd but whom I mostly enjoyed, summarized dozens of reference points — from Johnny Thunders‘ booziness and The Raspberries‘ ebullient heartbreak to the Laurel Canyon scene of the late ’60s — into druggy, delay-heavy come-down pop. It was exactly the stuff you’d expect from a songwriter who grew up in a cult. And I was prepared to drink the Kool-Aid myself, right up to the final song of the set, whose chorus went “Love is everything I need,” soon followed by “kissing and hugging is the air that I breathe.” Maybe singer Christopher Owens, shaggy and rail-thin, was being earnest. But I sensed contempt.

Photo by Benjamin R. Freed