One of Zeppelins finest compositions is immeasurably enhanced by the brilliance of Sandy Denny from Fairport Convention completely stealing the show. Written on a mandolin by Jimmy Page, the vocals are delivered in a narrator/crier format; Plant crooning the lead and Dennys hauntingly beautiful voice responding with lyrics drenched in Tolkien-esque imagery. Indeed, the song is said to directly reference the third Lord Of The Rings novel and while that may seem overly twee nowadays, the sheer beauty of the duos vocals elevate this song into a folk classic.