Led Zeppelin first recorded this song in 1971. it was intended for Led Zeppelin 4, but was put on Physical Graffiti to fill the double album. This song is about a man dodging a military draft, according to Robert Plant. Despite the title, it has nothing in common with: The album by Moody Blues, the 1933 Clark Gable film, the novel by Antoine de Saint Exupery, or the groundbreaking, classic, 1980s, USA network TV series Night Flight, which we will never shut up raving about because it is just that many tons of awesome.
Most of this song was written by Led Zeppelin's bass player, John Paul Jones, who is listed first on the writing credits. It is one of the few Led Zeppelin songs with no guitar solo.
While there's no official live recording of the band playing this, bootlegs abound of one time when they did it during a sound check on stage. A different studio version was produced with extra backing vocals.
In the liner notes for the Led Zeppelin box set, Jimmy Page declares: "To be able to fuse all these styles was always my dream in the early stages, but now the composing side of it is just as important."
In Frank Moriarty's book Seventies Rock: The Decade of Creative Chaos, Moriarty recounts how critics were less receptive to Zeppelin's stateside invasion than their fans: "The writers insisted the band's concerts did little more than placate legions of Quaalude-swallowing, whiskey-and-wine-swilling cretins, a vulgar audience that filled the soulless hockey rinks and municipal auditoriums of the United States - and Led Zeppelin was more to be blamed for the group's low-rent audiences than praised for their music." Good thing their reputation recovered, then!