Behind the character of Don Juan lay a long tradition going back to the Renaissance. Behind the stanza used in "Prospectus" and "Beppo" also lay a long tradition going back to the Renaissance. These two traditions are combined in Don Juan. Chief among the Italian Renaissance writers who had combined serious and comic matter are Luigi Pulci (1432-84) and Francesco Berni (1496 ?-1535). The tradition was carried on in the eighteenth century by Giambattista Casti. After becoming acquainted with the mock-heroic manner in Frere, Byron steeped himself in its Italian practitioners. He had begun to study Italian in 1810, and was particularly fond of Casti.
Ottava rima, or eight-line stanza, was the poetic form favored by the Italian satirical writers of mock-heroic romances. The rhyme scheme of ottava rima, abababcc, is a demanding one and for that very reason encouraged the use of comic rhyme such as Byron employed so extensively in Don Juan. The concluding couplet can be used to end the stanza with a witticism or a swift fall from the lofty to the low or a surprise for the reader in the form of a pair of unexpected and clever comic rhymes. Byron, as a devoted disciple of Pope, who wrote almost exclusively in iambic pentameter couplets, was fond of couplets and for this reason alone would have found the ottava rima stanza attractive. In the course of writing Don Juan Byron became very skilled in the handling of the challenging rhyme scheme of ottava rima. His ability to create outrageous rhyme is unrivaled. His mastery of his stanza pattern pleases the reader, whether he is aware of it or not. Ottava rima helped to make Byron the great comic writer that he is.
For example, in the first stanza of Canto XIII Byron writes:
I now mean to be serious; — it is time,
Since Laughter now-a-days is deemed too serious;
A jest at Vice by Virtue's called a crime,
And critically held as deleterious:
Besides, the sad's a source of the sublime,
Although, when long, a little apt to weary us;
And therefore shall my lay soar high and solemn,
As an old temple dwindled to a column.
In this stanza Byron alternates masculine (single) with feminine (double) rhymes and concludes with feminine rhymes. The rhymes are perfect and pleasing to the ear. In addition, in his climactic concluding line he coins a simile that is both fresh and striking. Italy, where Byron wrote his Don Juan, is full of "old temples dwindled to a column."