Aqualung

Anderson wrote the song with his then-wife Jennie Franks, starting from a photograph she took of a tramp in London. He told Guitar World in 1999 that the idea came from that photograph, and that he worked out the verse chords in an L.A. hotel room.

Martin Barre said that when he recorded the solo, Jimmy Page walked into the control room waving, and Barre could not wave back without risking the take. The song was never a single. Anderson told Songfacts it was too long and too episodic. After "Locomotive Breath" it is the song most often played in concert by the band. The solo is number 20 in Guitarist magazine's list of the 20 greatest guitar solos.