Ready the cattle for joyous sacrifice: Slint are coming to town. After 15 years apart, the legendary post-rock outfit has briefly reunited to take their moody, narrative soundscapes on tour. For a small segment of the population, this is an occasion for rapture and celebration. For a subset of that segment, it’s an opportunity for indie disdain.

The Slint story is legend that had begun to recede into memory. In 1987, guitarist/vocalist Brian McMahan and drummer Britt Walford hooked up with guitarist David Pajo in Louisville, Ky., and Slint was born. The group responded to the aggression of hard-core and the vacuousness of arena rock with something new – sprawling songs that vacillate between hypnotic and abusive, jumping across bizarre time signatures while switching from whispered lyrics to raucous, screaming jam sessions. They released two albums, had some nice things said about them, and disbanded in 1991.

Except, of course, that wasn’t it. “Spiderland,” their second LP, had the slow burn trajectory of many important albums; little noticed at first, by the mid-1990s it became definitive of a new genre. Dedication to Slint became de rigueur for the knowing hipster, and a lot of (confusing) names were attached to this sound: post-rock, pre-rock, new prog, math rock.

As defined by Slint on “Spiderland,” it’s probably best described by its definitive components: Pajo plays eerie, developing guitar phrases as McMahan speaks or sings rambling, imagistic narratives that are surprisingly warm but always opaque. Walford roots the brooding mix with a slow back-beat. Then, the whole thing builds to chaos – the vocals scream and fall silent, the two guitars wail and duel, meter skips wildly (although tempo generally remains a slow drive), and the band swells to a thick, wall-of-sound climax. Most Slint songs repeat this three or four times.

It’s tempting to be skeptical of the devotion Slint engenders (it’s pretty easy to become expert in a band’s oeuvre when they only officially released 17 songs, after all), but their soft-loud-soft dynamic and swelling composition influenced everybody from The Pixies to Mogwai, and their free-form structure and lyrical dreaminess can be seen in bands as diverse as Deerhoof and The Shins. If you like any stripe of nonchart rock (and some charters as well – the aforementioned Shins and Modest Mouse come to mind), then you’re probably listening to artists influenced by this weird little band.

Slint is playing at Irving Plaza on March 17, 18, and 19 at 8 p.m. (17 Irving Place, between East 15th and 16th Streets, 212-777-6800).