As the 1980s dawned, the metal genre underwent a significant transformation. In response to the onslaught of the new wave of British heavy metal on both sides of the Atlantic, the Bay Area scene began crafting a response to acts like Diamond Head and Saxon. Lars Ulrich and James Hetfield laid the groundwork for Metallica, initially known for crafting impeccable thrash metal. However, one of their early classics drew inspiration from an unexpected source – southern rock.

Metallica, despite their prominence in the metal scene, were never genre snobs when discussing their musical influences. Hetfield, when sharing his favorite songs, expressed interest in classic rock as much as heavy metal, placing acts like Van Halen and Aerosmith on the same pedestal as Black Sabbath and Judas Priest.

Bassist Cliff Burton played a pivotal role in broadening Metallica’s musical horizons. Unlike the standard heavy metal of the time, Burton embraced complex material, ranging from Kate Bush and The Police to King Crimson and beyond.

Even before the band solidified its lineup, Metallica’s penchant for weaving different riffs together emerged on the song “The Four Horsemen.” Based on a bluesy shuffle rhythm explored by original guitarist Dave Mustaine, titled “The Mechanix,” Hetfield contributed to shaping the song’s structure, incorporating lyrics about the four horsemen of the apocalypse.

During rehearsals, Mustaine injected a bit of humor by playing Lynyrd Skynyrd’s “Sweet Home Alabama” in between takes. Ulrich, unfamiliar with the song, found Mustaine’s metallic rendition of the riff to be a perfect fit for “The Four Horsemen.”

Mustaine later shared that the Skynyrd riff started as a joke but ultimately became an integral part of the song. He recounted, “We get to rehearsal, and Lars says, ‘We have to slow this song down, man.’ So I played the ‘Sweet Home Alabama’ riff, and he said, ‘Fuck, man, that’s brilliant.’ So that’s the difference between ‘The Four Horsemen’ and ‘The Mechanix’. The bastardised version of Lynyrd Skynyrd.”

While Ulrich had not heard the original song, Lynyrd Skynyrd was already deeply ingrained in Hetfield’s musical DNA. Growing up with country music, both Hetfield and Burton held a profound appreciation for Skynyrd, particularly on tracks like “Freebird” and “Tuesday’s Gone,” the latter of which Metallica would cover on their album Garage Inc. When Mustaine parted ways with the band, the song underwent significant changes.

Despite Mustaine’s request not to use his material, Metallica recycled his riffs, turning “The Four Horsemen” into a standout track on their debut album, Kill ‘Em All. The incorporation of the “Sweet Home Alabama” riff, although not met with legal action from Lynyrd Skynyrd, became a hallmark of the song. The breakdown’s medium tempo provided a calming interlude, setting the stage for subsequent episodic songs like “Master of Puppets” and “Welcome Home (Sanitarium).”