By JON PARELES

Published: November 11, 2004

Isaac Brock took a moment during Modest Mouse’s set to look around Radio City Music Hall on Tuesday night. “This place seems a little fancy for us, but it’s real nice,” he said. After years on the club and college circuits, Modest Mouse is suddenly above the pop horizon, with video clips on MTV and over a half million sales of its current album, “Good News for People Who Love Bad News” (Epic).

The album tunes up and cleans up some of the band’s old low-fi quirks. But the band treated Radio City like a big club, casually taking its time between songs and working through each tune without overt showmanship. For most of the set Mr. Brock wore a broad-brimmed cap that hid half his face. Modest Mouse isn’t likely to be mistaken for slick anytime soon.

There’s always something a little askew in Mr. Brock’s songs. His voice starts out unglamorous, nasal and quavery with a drawl that comes and goes, and he pushes it, shouting or cackling with sudden bursts of vehemence or petulance. The band’s tempo may suddenly lurch into a different gear, and sometimes a discordant guitar will start strumming away or blast into the foreground. It’s all deliberate; Mr. Brock is a misfit who makes himself worth knowing.

His lyrics muse on life and death, the origins of the universe and his personal failings, veering from optimism to fatalism: “We have one chance, one chance to get everything right,” he sang. “And maybe we might.”

The music matches his crankiness, refusing allegiance to any particular structure or style. Its roots are in the late 1970’s and early 80’s, when punk had smashed old notions of virtuosity and arty types were cobbling new structures out of the shards. What those bands discovered was the power of the arbitrary, the stubborn joy of knocking together a beat and sticking to it until its mannerisms began to sound natural.

In a set that relied on recent songs, Modest Mouse could sound like a skiffle band that had discovered minimalism, a folk-rock band with loose ends or a sprawl of clangorous guitars.

With two drummers, the band could sock out a simple beat or play ratcheting, overlapping grooves; its songs sometimes recalled the Talking Heads of “Speaking in Tongues.” In any configuration, Modest Mouse sounded willful above all, daring its new audience to accept every last idiosyncrasy.

Modest Mouse is to perform on Saturday on “Saturday Night Live,” at the Aragon Ballroom in Chicago on Dec. 4 and at the Crystal Ballroom in Portland, Ore,. from Dec. 13 to 16.