When one Googles the name "Stephen Immerwahr," the first result is a LinkedIn profile. And there on his résumé between "Researcher: Public Agenda" in the late '80s and "City Research Scientist: NYC Department of Health and Mental Hygeine" in the present, there's a lowercase nod to the five years that made the frontman and his bandmates legends to a stripe of patient indie-rock fans: "bass. Codeine. 1989-1994."

Immerwahr doesn't usually mention this chapter of his life to his coworkers. "People at my job have been finding out, partly because I've been carrying my bass to work, to then go to rehearsals," he says. "So that had to come out, which is blowing my reputation as a very formal, crotchety older guy at work. It's my shameful rock 'n' roll past."

Almost two decades after a quiet and amicable breakup, Codeine is back. Like countless '90s indie-rock outfits, the trio has found that sentimentality and Internet access have made for a more fertile fanbase than it ever experienced the first time around. But Codeine's members are as skeptical of these reunions as you are. When his bandmates asked Immerwahr about getting the group back together—the All Tomorrow's Parties festival had been asking them for some time—he emailed his response: "I would be willing to do up to 10, or possibly 11 live performances." In all, the band will play something closer to 16.

Rare are the groups that pioneer a sound, but Codeine did. The band traded in heavy, feedback-laden guitar and a glacially slow, minimal rhythm section—often dubbed "slowcore"—that bucked the quick and dirty conventions of the era. Immewahr's vocals dredge along with the music's low-end, mimicking the guitar lines and only occasionally peaking above the muck. The result is tense and sometimes disheartening music that retools the classic rock 'n' roll rewards system. Verses often become indistinguishable from choruses, but the band's emotional releases—as rare as goals in a soccer game—are entirely addictive to fans.

That wasn't how the band began. "At the time of our first show, there was a wider array of styles," says guitarist John Engle. "We thought it couldn't all be this slow, clanging, morose-sounding stuff. But by the time of our second or third show, we said, 'Wait, yes they can.'"

"We wanted a coherent aesthetic," Immewahr says. "A coherent visual aesthetic and style, and something that integrated the emotional content of the songs, as primitive as the lyrics might have been. Limiting ourselves to that gave us a certain kind of strength, but it may have made it ultimately more difficult for the band to grow and keep going."

Codeine did grow, albeit—like most things in the band's world—in small increments. Where 1990 debut Frigid Stars was aching, brutal and lo-fi, the Barely Real EP introduced newly descriptive songwriting and cleaner instrumentation that allows listeners to discern between instruments. The band's swan song, White Birch, opens with a seven-minute epic called "Sea" and digs deeper valleys and builds higher peaks than either of its predecessors. But taken as a whole (perhaps not in a single sitting), the catalog—recently reissued on vinyl by the Numero label—offers a peculiar feeling of relief and resolution. The world doesn't need another Codeine album. But for those influenced by the records—a list that includes bands from Bedhead to Mogwai—a tour is a very welcome prospect.

"For a long time we'd say, 'Maybe we'll be the one band from the '90s that doesn't get back together,'" says drummer Chris Brokaw. "And we felt pretty good about that.” 

But in playing just a handful of shows, the band members hope each night will feel special. So far, they all have. "We never had such receptive audiences back in the day," Immerwahr says. "I hadn't thought about people living with those records for a long time and what it might mean to them. I also didn't know how much I'd like being back onstage."

He hasn't missed it enough to return to music full time, though Immerwahr admits the experience may change his work apparel. "I thought about coming back from our tour with leather pants," he says. "And maybe a Jimi Hendrix hat with the wide brim and the silver buckles on it.” 

SEE IT: Codeine plays Doug Fir Lounge, 830 E Burnside St., on Wednesday, July 11. 9 pm. $15. 21+.