For years, I’ve mistakenly thought of Black Sabbath as a one-trick pony—probably on account of the monotony of the horde of copycats citing their catalogue as their bible.

But after digging deeper into their discography, I can see now that the source material is much more diverse than I could have imagined. Vol. 4 is especially varied, and not just in comparison to their other records, but within its own tracklist.

While Black Sabbath’s trademark “low and slow” churn is in full force here, it largely acts as the foot of a compass, keeping the group centered while they swing outward. I’ve seen flashes of Sabbath’s importance across Paranoid and Master of Reality, but with Vol. 4, I finally understand the full magnitude of their influence. While the earlier records clearly laid out the blueprints for doom and stoner metal, this record shows the entire family tree of metal sprawling up from it. All of the branches breaking off from Iron Maiden or Metallica or Death sprouted from these roots.

“Wheels Of Confusion” opens the record with a churning doom riff before transforming into a headbanging anthem, shifting tempo and mood several times along its eight-minute run time “Changes” strips away all of the pounding drums and wailing guitar and replaces it with a mournful piano ballad. “Supernoid” rushes headlong with a reckless abandon that forecasts Van Halen and Motörhead. “Snowblind” is a ballad played as heavily as possible, until exploding into a riffy shuffle in the closing moments. The acoustic instrumental “Laguna Sunrise” strums pensively on odd chord changes, offering a moment to breathe between rippers. “Under The Sun” closes the record with one of their heaviest riffs ever.

Even though I’m coming into metal relatively recently through bands like Alcest, Isis, Pallbearer, and Deafheaven after years of dismissing metal over deathcore, numetal, and all of the Black Sabbath ripoffs, I’m finding a deep, deep appreciation for Black Sabbath themselves, who I’m learning didn’t just influence metal, but also created some of the most incredible metal records of all time. Old news, I know.