How did Edgar Allan Poe alter traditional ballad form in “Annabel Lee” and “The Raven”?

Traditional ballads typically follow a strict structure consisting of four-line stanzas (quatrains) with an abcb rhyme scheme and alternating lines of four and three stresses. Edgar Allan Poe significantly altered this form in his works by experimenting with stanza length, rhyme, and meter.1

In "Annabel Lee," Poe departed from the standard quatrain by utilizing stanzas of six, seven, and eight lines. Furthermore, he abandoned a consistent rhyme scheme; for instance, the first stanza follows an ababcb pattern, while the second stanza employs an abcbdb scheme.1

Poe pushed these formal deviations even further in "The Raven." He employed six-line stanzas and a specific abcbbb rhyme scheme. Additionally, he introduced a complex metrical pattern that varied significantly from the traditional ballad’s alternating stress count, incorporating unique line lengths and stressed syllables to create a distinct rhythmic effect.1