Originally released in November 1971 as a single in an early form, the song was re-recorded during the Solid Air sessions. The new version became something of a signature song for Martyn, as well as a staple of his live performances.
When Martyn re-recorded the song for Solid Air, he just couldn't nail a take that he was satisfied with. The night before producer John Wood was due to fly to New York to master the album, he was still waiting for the tape containing this tune. "It was by then nearly midnight," he recalled to Mojo magazine April 2013, "so I said to him, For Christ's sake, John, just go back down into the studio and play it again, and we'll record it. And he did, and it's great."
Eric Clapton covered this on his 1977 album Slowhand.
Kid Rock's "All Summer Long" is a mashup of "Werewolves Of London" and "Sweet Home Alabama." The album it came from was released in October, 2007, but they held off until summer, 2008 for a more seasonable release.