Terza rima is a type of rhyme scheme built upon interlocking series of rhymes that occur in tercets. A tercet is a stanza that consists of three lines, much as a couplet is a two-line stanza and a quatrain is a four-line stanza. This three-line structure is integral to this particular rhyme scheme. Terza rima essentially consists of a rhyme scheme that appears as “aba, bcb, cdc, ded,” in which the rhyming sound introduced in one stanza continues into the next, which then introduces the rhyme for the next stanza.
The rhyme scheme known as terza rima was created by the Italian poet Dante Aligheri as he composed his Divina Commedia or Divine Comedy. This epic poem consists of three sections called Inferno, Purgatorio, and Paradiso, which depict the poet’s journey down into Hell, up through Purgatory, and finally into Paradise, or heaven. Written in the early 14th century, the Divine Comedy is a massive work that largely deals with Catholic themes of sin, punishment, forgiveness, and the universe as created by Dante’s ideal Christian God.
Terza rima is essential to the structure of the Divine Comedy and has become so closely related to the work that any use of this rhyme scheme is almost inherently seen as an allusion to Dante’s poem. The structure of terza rima begins with a poem written as a series of tercets, or three-line stanzas. A rhyme scheme is used throughout these tercets in which each line does not rhyme with the next, but with the line after it. This continues for three rhymes, at which point a new rhyme takes over.
The structure of terza rima can be most easily visualized as “aba, bcb, cdc, ded,” in which each letter represents an ongoing rhyme. Other than the beginning and end of the poem, each rhyme can be repeated three times and these interlocking chains of rhyme can essentially go on forever. This structure pulls the reader through the poem, creating a sense of visual momentum, as each tercet continues the previous rhyme and introduces the next one. The reader naturally continues reading with a subconscious desire to see the rhyme play out from one tercet to the next.
Terza rima is essentially based on a trinity, and is often seen as a way in which Dante made the structure of his poem reflect the concept of the Holy Trinity within Catholicism. Since the Holy Trinity is said to be eternal, this concept is reflected well in Dante’s structure, since the rhyme scheme has essentially no proper beginning or end. The limitations of human poetry, however, require a beginning and ending point that are imperfect within the poem. This may reflect Dante’s humility in creating a poetic structure meant to mimic his idea of the eternal and omnipotent, but restricted by human limitations.