Isaac Brock, singer and primary songwriter of Modest Mouse, performs a sold out show at the 9:30 Club on Wednesday. (Josh Sisk/For The Washington Post)

For the past five years, Modest Mouse has been effectively MIA. The Portland, Ore.-based band led by singer and guitarist Isaac Brock released its most recent full-length record, “We Were Dead Before the Ship Even Sank,” in 2007 and, so far, the closest it has come to a follow-up has been the singles and B-sides compilation “No One’s First, and You’re Next.” Even that has been collecting cobwebs for two years now. But anybody who saw the band perform at the 9:30 Club on Wednesday night — the first of two sold-out D.C. dates — with hopes of finding the group refreshed and re-imagined, perhaps road-testing an album’s worth of new material, probably left disappointed. In Modest Mouse time, it’s still 2007.

Brock and his band, which is staffed largely with unfamiliar faces (founding bassist Eric Judy was notably absent, and Smiths guitarist Johnny Marr, who briefly joined in 2006, is long gone), performed a two-hour set that leaned heavily on the band’s back catalogue. The two new songs they did perform — the shuffling “Heart of Mine” and space-y ballad “Ansel” — were slight and un­memorable, outshined by a well-arranged cover of Bob Dylan’s “You Ain’t Goin’ Nowhere.”

But the old stuff has been well maintained, at least.

Formed in 1993, when Brock, Judy and drummer Jeremiah Green were in high school, Modest Mouse gave its early songs a distinctive, slippery musicality. Because the trio was largely self-taught, it approached its instruments in untraditional ways — Judy’s wobbly bass lines often carried the songs’ core melodies rather than the rhythmic bottom, and Green’s drum rhythms involved a lot of primitive and cyclical pounding. The music was messy but memorable.

Since then, things have been tweaked and professionalized. In its current live incarnation, Modest Mouse has expanded into a septet, with two drummers, a keyboardist, an extra guitar and a violin. But on such songs as “Dramamine” and “Broke” — among the oldest tunes in the set — the larger ensemble stayed true to the music’s warbly, spaced-out roots.

Isaac Brock, singer and primary songwriter of Modest Mouse, performs a sold out show at the 9:30 Club on Wednesday. (Josh Sisk/For The Washington Post)

Modest Mouse has had some bona fide hits — “Float On” was nominated for a Grammy — but the band’s darker and jammier moments, such as the sinister and atonal “Tiny Cities Made of Ashes,” seemed to draw the bigger cheers from the crowd.

Although it has experienced some popular crossover in the past decade, Modest Mouse built its audience on the strength of Brock’s bizarro rambling — his surreal Sam Shephard-meets-mall-punk narratives and his ability to perfectly crystallize stoner thoughts into lyrics (“Every time you think you’re walking you’re just moving the ground” or “The stars are projectors, yeah, projecting all our lives down to this planet Earth”). Those songs and their strange but delicate sentiments still hold up. Hopefully, they’ll continue to do so until Modest Mouse can write some more. It might be a while.