A self-described “minimalist rock trio,” Shellac are a band who’ve succeeded despite their severe disinterest in the standard operating procedures of the music business, even by the relaxed standards of indie rock. Shellac (or, as they sometimes bill themselves, Shellac of North America) don’t tour very often, they release recordings even less frequently, they do little if anything to promote their albums, their live appearances have more to do with places they’d like to visit than what constitutes a good market, and they have no interest in making their work user friendly. Despite this, Shellac have won a loyal international following for their jagged but rich blend of fractured, metallic-sounding guitar (literally metallic, as guitarist Steve Albini favors aluminum-neck guitars and copper picks), deep throbbing bass, and drumming that serves as both rhythmic foundation and melodic punctuation. Featuring three noted figures from underground and independent music — Steve Albini, Bob Weston, and Todd Trainer — Shellac’s sound, informed by noise rock and math rock, was introduced on a pair of 1993 singles, The Rude Gesture: A Pictorial History and Uranus, and while they expanded into longer and more adventurous structures on 1998’s Terraform and 2007’s Excellent Italian Greyhound, the musical signature and the vital interplay between the three musicians remain distinctly their own, leaving room for improvisation and creative experimentation within their artfully burly sound.