The lyrics of "Magnu" are based upon Percy Shelley's poem "Hymn of Apollo". The song is a popular live number, being performed occasionally over the years, versions on the albums "" (1982), "The Friday Rock Show Sessions" (1986) and "Canterbury Fayre 2001". The first six lines of Magnu are nearly word for word identical to a magical chant that appears in an old Slavic folk-tale, "The History Of Prince Slugobyl; Or, The Invisible Knight", used to summon the magical horse, Magu (sic), first published in English translation in 1896 in "Fairy tales of the Slav peasants and herdsmen."