By the early 1990s, Lou Barlow was used to getting some weird fan mail. The lyrics he wrote for his band Sebadoh seemed to excavate the loneliest and weirdest secrets of his inner world — subject matter that invited Barlow’s listeners to form an unusually close relationship to its singer. He didn’t think much of it when one of those fans, a teenager named Harmony Korine, sent him the full-length script for a pretty out-there movie he’d written called “Kids.”

“It seemed kind of extreme, but I was used to it,” Barlow recalled in a video interview. He began corresponding with Korine, who wanted Barlow to write the music for his film, which was not some pipe dream but actually in an early state of production. Korine, he said, had a clear vision: “He obviously knew what he was talking about.”

Directed by photographer Larry Clark, “Kids” would indeed become a cultural flashpoint upon its 1995 release for its colorful, and arguably exploitative, depiction of wayward New York City teenagers caught up in drugs and sex. It would serve as a launchpad for Korine’s own directorial ambitions, and the careers of actresses Chloë Sevigny and Rosario Dawson. And for many viewers, the “Kids” soundtrack was an introduction to some of the stranger artists in then-contemporary American independent music: outsider singer-songwriter Daniel Johnston; mysterious post-rock practitioners Slint; and the Folk Implosion, Barlow’s eclectic band with John Davis, who ended up scoring a good chunk of the movie.

An incomplete version of that soundtrack is available on some streaming platforms, but it cannot be heard as it was initially presented. (Multiple songs — different ones — are missing on Apple Music and Spotify; the LP isn’t on Tidal or Amazon Music.) A Domino publicist said in an email that Universal — the parent company of London Records, which first released the “Kids” soundtrack — no longer held the rights to any of the music, and that “a partial selection had become available erroneously.”

But now, the Folk Implosion’s contributions to that soundtrack has been reissued Sept. 8 via Domino Records as “Music for Kids.” It contains all the original compositions the band made for the movie, many of which have never been available on streaming, as well as a grab bag of sonically similar Folk Implosion recordings from subsequent albums. “Music for Kids” also doubles as a flagship release for the duo’s reunion. Davis left the band in 1999 on unfavorable terms; today, they’re working on new Folk Implosion recordings, and making plans to perform together.

“There’s a core spark to it that feels almost genetic,” Davis said in a separate video interview.

Their collaboration as the Folk Implosion was, in fact, inspired by a fan letter that a teenage Davis wrote to Barlow in the late ‘80s, when Barlow was living in Westfield, Massachusetts. At the time, Barlow was beginning to gain attention for his work in Sebadoh, following his stint as the bassist in the alternative rock band Dinosaur Jr. His experience with the indie music scene had made him acutely aware of its limitations, and in Davis, he found a cerebral collaborator who wasn’t afraid to talk freely about the creative process.

“John, he’s an actual intellectual,” Barlow said. “Him being a fan of my work really made me feel safe — that I could just start talking.”

The two never seemed to encounter much resistance as they worked on the soundtrack, which they made without a restrictive budget. (They were paid a flat fee: “I know our lawyer thought it was low, whatever it was,” the band wrote in an email.) The lack of guardrails led to its biggest single, “Natural One.” Conceived for a scene where a group of teenage girls talk frankly about their sex lives, the song was ultimately left out of the final cut. (In its place, Korine inserted a Beastie Boys track.) Nonetheless, the Folk Implosion refused to consign it to the archives.

“We didn’t know it would be popular, but we knew that we’d done something very good,” Davis said. After the movie was finished, they received some extra money from London Records that allowed them to add vocals and complete the song. Upon its release and promotion, “Natural One” reached an unlikely position of No. 29 on the Billboard Hot 100.

The surprise hit invited plenty of attention from curious labels, appropriate in a post-Nirvana era when plenty of big-money contracts were handed out to underground acts. The Folk Implosion signed with Interscope, but the ride wouldn’t last long. Barlow found himself in the untenable position of having to reassure his Sebadoh bandmates that his attentions weren’t divided, which became increasingly difficult.

“For all the success I was having, I still had a pretty remarkable lack of confidence,” he said. And Davis became conflicted about participating in mainstream entertainment, which exacerbated his own anxiety about becoming a public figure.

Slowly, their relationship started to fray. Davis ended up quitting the band after the release of “One Part Lullaby” in 1999, their only record for Interscope. They would not speak for more than 20 years. But near the start of the pandemic, they became Facebook friends. “I started thinking to myself, ‘What if Lou died, and we never talked to each other again?’” Davis said. After a handful of online interactions, they reconnected over the phone, where they hashed out some of those long-standing issues. They raised the possibility of collaborating again, which led to the “Kids” reissue and their upcoming plans for the Folk Implosion.

“It’s virtually the same,” Barlow said, of their resumed friendship. As Davis listened on, he explained he was “happy to change the ending” of what had been a sad conclusion to an otherwise fruitful experience.

“I don’t think anything’s actually finished until we’re gone,” he said. “I would like to think of us in terms of folk or jazz musicians — people who keep playing music until they dropped dead.” Working with Davis again, he said, had reminded him of the excitement of their initial collaboration. “I could never predict where those songs would end up,” he said. Now, as their new songs have taken shape, “they always surprise me.”