Keats wrote the poem as a ballad, one of the oldest forms of poetry in English literature. A ballad is traditionally a rhyming song of many stanzas and narrates a tale. The balladic stanza is commonly a quatrain or four-line verse, with a rhyming scheme of ABAB or ABCB. Meant to be sung aloud and passed from one generation to another, the ballad is rhythmic and smooth-flowing. “La Belle Dame sans Merci” contains 12 quatrains with an ABCB rhyme scheme. The meter is largely iambic tetrameter, with the stress falling on four words per line, such as: “O what can ail thee, knight at arms” (Line 1). So far, the poem seems to be following a traditional balladic form. The twist occurs in the fourth line of each stanza, which is abruptly shortened, breaking up the flow of the previous three lines. Pointedly, this last line is only three or four words long and consists of just three stressed syllables. An example is the change in length and meter between Lines 2 and 4, from “Alone and palely loitering?” to “And no birds sing.