Modest Mouse’s Isaac Brock writes songs that burp, bubble, sort of groove, and then eventually peter out. The musician’s career thus far can be seen as an anguished plea to be taken less than seriously (title of MM’s debut: This Is a Long Drive for Someone With Nothing to Think About), but his songs hint of an ambition matched by an ego. The long ones unfold in movements, and they all play like epics, even the brief ones. Ugly and beautiful, focused and frazzled: With an unsteady hand, Brock fires a single bullet and nails them all.

Today, almost a decade after Kurt Cobain cracked Billboard’s code with a don’t-listen-to-me punch line, it’s still amazing to see how much mileage a sensitive guy can get from squeezing the sparks out of his own emotions—especially when said guy knows where to push and prod. Like most career-minded indie rockers, Brock plays the hard guy because he’s come to understand that it’s his best option: Saps go sour quick, and nice guys don’t get paid.

When he spills his guts, the nasty bits shoot out like darts, often boomeranging back. “Out of Gas,” a plodder from Mouse’s ’97 release, The Lonesome Crowded West, includes the confessions of an unrepentant bore: “I had a drink the other day/Opinions were like kittens/I was giving them away.” On “3rd Planet,” the opening track of The Moon and Antarctica, Mouse’s major-label debut, Brock almost runs out of breath as he sings, rather sweetly, “I got this thing that I consider my only art/Of fucking people over.”

On Tuesday of last week, the line sailed right over the Black Cat’s sellout crowd, and it wasn’t just because few people had heard “3rd Planet” before. (Antarctica doesn’t come out until June 13.) When Mouse isn’t hot-wiring funk and punk with bastard blues, it’s couching Brock’s honesty in shapely melodies that turn corners just before taking your breath away. “3rd Planet” is basically four minutes of direction shifts—a diary-torn pop ditty colliding into herky-jerky indie rock colliding into OK Computer. On Tuesday night, “3rd Planet” followed West’s “Polar Opposites,” which was similarly stunning. While Brock summoned up an alcoholic’s nightmare (“I’m trying to drink away the part of the day that I cannot sleep away”), a second guitar set off on a desperate search for sunshine.

On the three full-lengths leading up to Antarctica (the rarities collection, Building Something out of Nothing, came out late last year), Modest Mouse established itself as the post-punk ambassador from rock’s fading underground. How exactly the band rose above the fray is anyone’s guess, but talent, charm, and taste all had to have played roles. A trio on paper (touring guitarist Robin Perringer rounded out the lineup on Tuesday), Mouse in its early days touched on the kind of influences (Pixies, Pavement, Meat Puppets, Husker Du) that no doubt reminded a few label honchos of alt-rock’s salad days. You’ve also got to like the potential of a band whose members are still in their early 20s after seven years of road work.

West was Mouse’s real eye-opener, a smart-alecky, hard-bitten opus that introduced indie-rock fundamentals to the lonesome-white-boy blues, and Antarctica is its equal, although the transcendence on the new record sounds less stumbled-upon. True to his roots, Brock is suspicious of the mainstream. On West, he manages to sing “Goddamn right I’ll be heard” without actually meaning it—he’s just riffing on the stuff that the punk-rock bands his parents liked would say to sell records.

There are fewer such winks on Antarctica, probably because there wasn’t any room for them. Productionwise, the record contains few departures—just some acoustic-guitar texturing and a lame stab at roboto-rock called “Tiny Cities Made of Ashes.” But the songs on Antarctica are less oblique than any that Brock’s written before—a symptom, I’m guessing, of real life interrupting his visions of growing up too fast. In spring 1999, a Seattle woman filed a police report accusing Brock of rape. The charges were dropped, but Brock fled Washington state for a while. “Paper Thin Walls” may be the poppiest tune Mouse has ever released, but it still pointedly argues that living the boxlike life of the accused is a little like serving time.

A sex-crime allegation is a halo bender regardless of what the facts are, and it’s hard not to think that the Mouse guys have aged more in the past year than in the three previous combined. On Tuesday, I was struck by how much Brock didn’t seem like a chubby teenager anymore—not just because of his thinning features but because of the relative directness of his performance. During the tail end of “Never Ending Math Equation,” when the song exploded into a subhuman fit of grunting and guitar noise, Brock stood square, howling as he stared a hole into the back wall. It’s a trivial observation, perhaps, but the last time I saw the band, almost two years ago, Brock stood sideways with his eyes closed the entire night.

Mouse’s shows tend to be like its songs: well-structured but loosely fitted, meandering a bit here and there, and cranky. On Tuesday, the band mostly refocused its anger into jams: “Cowboy Dan,” a mean rocker about a mean drunk, was pure catharsis; it curled and swelled for eight minutes, prompting one concertgoer to actually execute a stage dive. (Remember those?) As always, “Doin’ the Cockroach” brought the house down, and the band turned “All Nite Diner” into an exercise in quirky, flat-footed funk that I won’t soon forget. When all was said and done, the cheap thrills outnumbered the heavy moments by a wide margin. Brock’s solo run through “Wild Packs of Family Dogs” during the encore was actually touching—it was the only time all night that he let his craggy voice really crumble. And then, a few songs later, he got into an argument with a fan, and the show was over. CP