The most important form here is the ode. We talked about that in the "What’s Up With the Title?" section, so you can go and read about it there. Let’s think about the rhyme scheme and meter in this poem. A lot of, ahem, other study sites will tell you that "Ode to the West Wind" is written in terza rima and leave it at that. That’s true, but terza rima is just one of the traditional poetic forms that Shelley is playing with here. Let’s cover both of them. Ready?
First, there’s terza rima, or "third rhyme," an Italian rhyme scheme most famously used by Dante in The Divine Comedy. (Go check out what Shmoop has to say about Dante's Inferno.) Shelley’s grabbing some extra poetic street cred by using a form associated with a great Italian poet who came before him.
The idea with terza rima is that the lines are in groups of three, and the middle rhyme of one set of three becomes the outside rhyme of the next set. Handbooks of literary terms will tell you that this means the rhyme scheme is "ABA, BCB, CDC" and so on. We prefer to think of it in a sandwich metaphor: the filling of each "sandwich" (or stanza) becomes the bread of the next one. Of course, it’s hard to end this form, because every set of three lines has a new middle that demands another set of three lines to use its rhyme. Shelley fixes this problem by following each set of four three-line stanzas with a couplet.
As if using terza rima weren’t enough to make "Ode to the West Wind" remind us of Dante, Shelley also divides the poem into cantos, the Italian poetry equivalent of chapters.
In this poem, Shelley also plays with another form: the sonnet. "Wait a minute," we hear you saying. "This doesn’t look like a sonnet. For one thing, a sonnet is a fourteen-line poem in iambic pentameter." Not too fast: "Ode to the West Wind" has five cantos, each of which is fourteen lines and ends in a couplet. That sounds suspiciously like an English sonnet. (Italian sonnets often don’t end in couplets.) And even though there’s a lot of variation in the number of syllables in each line, one could maybe generally call this iambic pentameter. Think about lines seven and eight: "The winged seeds, where they lie cold and low, / Each like a corpse within its grave, until" – hear that? Some iambic pentameter is peeking through here. So "Ode to the West Wind" is almost like a miniature sonnet sequence of five sonnets.
OK, so what’s the take-away message about the form and meter of this ode? Well, don’t forget that Shelley is an English expatriate living in Italy, writing, at least in part, about how frustrating it is for him to feel totally out of sorts in a different country. The poem imagines one solution to an individual feeling weak in the face of the world: unity between Man and Nature. But the form creates another solution: unity between a prestigious Italian rhyme scheme and a famous English style of sonnet writing. That way, Shelley the Englishman in Italy brings his two countries closer together with the structure of the poem.