Of all the seminal albums to come out in 1991—the year of Nevermind, Loveless, Ten, and Out of Time, among others—none were quieter, both in volume and influence, than Spiderland, and no band more mysterious than Slint. Few single albums can lay claim to sparking an entire genre, but Spiderland—all six songs of it—laid the foundation for post rock in the 1990s. Yet for so much obvious influence, both the band and the album remain something of a puzzle.