The only constant in Ben Chasny's longstanding Six Organs of Admittance project is change. Since 1998 he has engaged in composing, playing, improvising, and recording based on whatever aesthetic or philosophic principles appeal to him regardless of genre. More often than not, his records have existed between rather than within them, though there has always been a thread that marked a unique, if mercurial, signifier woven throughout to connect them. Hexadic is a different animal. Chasny spent some years developing a compositional system that would allow musicians -- guitarists in particular -- to break their learned habits and choices of riffs, vamps, solos, chord progressions, etc; in other words, a way to rethink music, making it from the ground up through use of the unconscious and unplanned. This album illustrates the system. Chasny designed Hexadic using a card system, as many composers before him have, from John Cage to John Zorn. Each card corresponds to one element of musical construction -- tone, changes, scales, even lyrics. But each player is allowed to interact with these cards in a free and open fashion. This makes for very open music, and that's the intention. The centerpiece is his guitar, but the rhythmic interactions that guide it are de-centered as well. While opener "The Ram" is skeletal and arid, all of its interplay is economical, with seemingly vast spaces between notes and tones. "Wax Chance" is its opposite, structured almost like an oddly metered blues; drums syncopate through and around the bassline while the electric guitar screams, howls, and pierces like Keiji Haino's with early Fushitsusha. "Maximum Hexadic" and "Sphere Path of C" are so aggressive -- with their drums and bassline playing triple- and double-time, respectively, around and through Chasny's assaultive scree -- they recall, but don't resemble, the jagged, disjointed, early PSF days à la White Heaven. "Hollow River" uses long, drawn-out riffs of feedback, sustain, and volume in a meandering, emotive crunch. "Future Verbs" meanders slowly and purposefully -- the sinister changes don't appear until midway through, and they are sparse. At its center are two repetitive guitar lines staggered in elocution and serving as near counterpoint. In closer "Guild," the screaming overdrive of Chasny's guitar vanishes a few moments in to be replaced by a gentle, swaying, elliptical melody unveiling its heart. Hexadic is at times harsh, unsettling, and even quizzical in its choices -- quizzical because even as listeners we make unconscious choices about what comes next. It may be a difficult go for fans of Six Organs of Admittance's more conceptual, musically unified approaches. But, for anyone willing to encounter it on its own terms, its alien nature is merely the first point of attraction. Devising a new way of playing heavy music is nothing if not a brave undertaking, and Hexadic rewards significantly with each repeated listen.