If Slint's debut, 1989's Tweez, was one of the earliest salvos in what came to be known as post-rock, their second album, 1991's Spiderland was where the band pushed their most radical ideas forward and created a touchstone, working with dynamics that made the silences every bit as much presence as the guitars and drums, manipulating space and time as they stretched out and juggled time signatures, and conjuring melodies that were as sparse and fragmented as they were beautiful. A large part of what makes Spiderland so memorable is the way Slint build so much from so little; there's a great deal of space in Brian McMahan and David Pajo's guitar patterns, but they mesh together in a way that brings out the strength in one another, and Britt Walford's drumming frequently abandons the traditional backbeat in favor of spacious, exploratory rhythms that add color and detail as much as maintaining the rhythms. (Todd Brashear's bass ultimately holds down the root of this music with greater force than anything else.) Music this powerful is rarely so quiet for so long, but Slint forge a tremendous dramatic tension in these 6 songs, and even when the chime of the guitars breaks forth into a roar, the result isn't a rent in the governing emotions of the songs as much as the logical conclusion this music was destined to take (the phrase "tone poems" may seem pretentious, but it really does fit these songs). It took years for Spiderland to be acknowledged as one of the most important indie albums of the '90s, and that seems fitting: this is music that demands a certain patience and participation from the listener, and word of mouth seems a curiously but absolutely fitting way to spread the word about a band that says so much with so few words. Alternately spectral and overwhelming, Spiderland is a singular achievement; plenty of bands would follow Slint's creative example in the years that followed, but few of them came close to the mysterious power and forbidding beauty of this music.