Debatably, Black Sabbath laid the groundwork for various subgenres of metal with individual songs from their early catalog, exploring cosmic psychedelia on one track, symphonic accompaniment on the next, and sludgy, downtuned riffing on the song after that. If the theory that Sabbath forecast a great deal of metal to come, Vol. 4 represents the earliest ancestry of doom metal as one of the band's darkest and most confused early documents. The three albums that came before 1972's Vol. 4 weren't short on dread and doominess, but the band's increasingly heavy mutations of blues-rock were kept from the brink of collapse by relatively streamlined production and aspirations for pop accessibility. By the time of Vol. 4, the band were certified rock stars, indulging in drugs and partying on an accelerated level. These excesses are reflected in the overall murky sound of the album, lyrical themes of a slippery grasp on reality, and weird stylistic curveballs that range from an out-of-nowhere soul breakdown in the middle of "Supernaut" (otherwise one of the most intense songs in the band's catalog) to stoned twiddling with delay effects on "FX" to the beautifully placid instrumental "Laguna Sunrise," consisting of Tony Iommi's classical guitar and full orchestral backing. This was the first album where Iommi and the band acted as producers, and their boundless experimentation went hand in hand with consuming ungodly amounts of cocaine, to the point where they originally wanted the album to share a title with its centerpiece "Snowblind," a plodding and bewildered ode to the drug. The record company ultimately vetoed the idea and the band acquiesced. Paradoxically, the scattered mindset and muddy atmosphere of Vol. 4 became its defining factors and resulted in some of the heaviest material the band would create. Ozzy Osbourne's patented wraith-like wails begin to come into their own on anguished rockers like "Tomorrow's Dream" and "Cornucopia," and take on a tenderness that Sabbath had never attempted before on the piano/Mellotron ballad "Changes." It's a somewhat awkward jerk from the tearful sentimentality of "Changes" to the paranoid proto-sludge of "Under the Sun," and many songs have similarly strange quick turns in composition, fumbling mixing choices, or different overall textural quality from track to track. Black Sabbath's collective mental state would further devolve on their next two albums, and by the late '70s they were virtually a different band. Though clouded by substance abuse, Vol. 4 found Sabbath at a creative peak that teetered on the edge of going off the rails completely. It's messy and bewildered, but stands as one of the band's most captivating and influential documents in all of its bizarre, damaged brilliance. ~ Fred Thomas