This feature revisits the origins of Led Zeppelin's Black Dog, the opening track on the band's untitled fourth album, tracing its distinctive rhythmic riff to bassist John Paul Jones. Jones has explained that the song's unusual structure has made it notoriously difficult for other musicians to replicate, and the article draws on his own account of how the idea first took shape, offering fans insight into the creative process behind one of the band's most celebrated songs.

Jones said he was inspired to develop the track's cartwheeling riff after listening to Muddy Waters' similarly shaped song Tom Cat, and jotted the idea down using a simple notation system his father had taught him while travelling home by train from a rehearsal at guitarist Jimmy Page's boathouse in Berkshire. Speaking to Mojo magazine in 2007, Jones recalled writing it "on a bit of paper on the train." Page himself praised the fourth album's creative force, saying it captured the band "coming in with full force," with Black Dog cited as a prime example.