This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Ottava rima's closing couplet, the final CC rhyme after six lines of alternating ABABAB, gives every stanza a small structural landing pad, a place where the verse can pause and comment on itself, and for two centuries of Italian epic that landing pad was mostly used for gravity: a summarizing line, a moral, a moment of pathos. Lord Byron read the same mechanism for exactly the opposite use. In Don Juan, the couplet routinely undercuts whatever elevated claim the stanza's first six lines just made, often with a joke, a bathetic rhyme, or a flat admission that the poem does not take its own high style entirely seriously. The form did not change to make this possible; Byron simply pointed a device built for gravity at comedy instead, proof that a stanza's formal architecture, the placement of its punch, can outlive any single tone its original users happened to fill it with.