Black Dog is a hard rock composition credited to John Paul Jones, Jimmy Page, and Robert Plant, recorded for Led Zeppelin's untitled fourth album (commonly known as Led Zeppelin IV) and released on Atlantic Records in 1971 as the album's opening track. Jones composed the core riff and arrangement, sketching it on the back of a train ticket after a rehearsal at Page's house, drawing partial inspiration from the sped-up rhythm of Howlin' Wolf's Smokestack Lightning. The piece is built around a relentless, interlocking bass and guitar riff that shifts between time signatures, creating a propulsive, carnal energy. Its structure employs an unusual call-and-response format in which Robert Plant's a cappella vocal phrases are answered by explosive full-band riff entries, a device inspired by Fleetwood Mac's Oh Well. John Bonham's drumming cuts through the rhythmic complexity by laying down a steady, driving four-on-the-floor pulse that gives the track its unstoppable momentum. The title came from a black Labrador retriever that wandered the grounds of Headley Grange, the Hampshire estate where much of the album was recorded. Black Dog stands as one of the defining tracks of early 1970s hard rock and a staple of classic rock radio. The original studio recording on Led Zeppelin IV remains the definitive version, and on AllSolos it is represented by Jimmy Page's electric guitar solo from that landmark 1971 session.