"Errantry" is a three-page poem by J.R.R. Tolkien, first published in The Oxford Magazine in 1933. It was included in revised and extended form in Tolkien's 1962 collection of short poems, The Adventures of Tom Bombadil. Donald Swann set the poem to music in his 1967 song cycle, The Road Goes Ever On. The poem has a complex metre, invented by Tolkien. It fits the tune of Gilbert and Sullivan's patter song, "I Am the Very Model of a Modern Major-General". It shares metre and rhyming patterns with the "Song of Eärendil", a poem entirely different in tone. The scholar Paul H. Kocher calls the pair "obviously designed for contrast". The Tolkien scholar Randel Helms calls it "a stunningly skillful piece of versification... with smooth and lovely rhythms". Tolkien described it as "the most attractive" of his poems. Poem Subject The J. R. R. Tolkien Encyclopedia describes "Errantry" as "the nonsensical adventures of a tiny messenger knight who falls in love with a butterfly and battles various insects." It adds that it is then linked to the Hobbit Bilbo Baggins's "serious account of Eärendil's quest" as described in Tolkien's 1954–55 novel The Lord of the Rings. The poem mentions creatures called Dumbledors and Hummerhorns. "Dumbledor" is an English dialect word for bumblebee, while according to the Tolkien scholars Christina Scull & Wayne G. Hammond, "Hummerhorn" is apparently a name invented by Tolkien for a large wasp or hornet. Metre Tolkien invented the metre, which consists of trisyllabic assonances, three in each set of four lines. The second and fourth line in every quatrain rhyme, as do the end of the first line and beginning of the second line in every pair. He found this so difficult that he never wrote another poem in this style, though he did later develop another style from this, and the result, through long evolution from Errantry, was Eärendil the Mariner, published in The Fellowship of the Ring. Joe R. Christopher, in the J. R. R. Tolkien Encyclopedia, writes that the poem could be seen conventionally as quatrains of iambic tetrameters with ABCB rhyme, but that the recording of Tolkien reading the poem shows the metre to be his own invention. In Christopher's analysis, each line is composed of "two second-class paeons", each consisting of an iamb and a pyrrhus: ˘ − ˘ ˘. There is an additional rhyme or half-rhyme of the ends of