“Ode to the West Wind” is made up of five numbered sections known as cantos. Each canto is equal in length and consists of four tercets and a concluding couplet, all of which rhyme according to a medieval Italian pattern known as terza rima. Broadly speaking, the poem’s five cantos can be grouped into two parts, which we could describe as the speaker’s poetic invocation and their revolutionary vision. The first part comprises cantos 1–3, in which the speaker develops their invocation to the west wind at great length. The invocation begins in the opening canto, where the speaker calls on the wind as both “destroyer and preserver” (line 14). Specifically, the speaker envisions the wind as a force that blows dead leaves off the trees, yet which also distributes them in a way that enables the seeds they carry to bring forth new life come spring. This first canto opens the speaker’s invocation by emphasizing the wind’s power to influence the terrestrial realm. In the two cantos that follow, the speaker extends their invocation by reflecting, in turn, on the wind’s capacity to sculpt the sky and churn the sea.

If part one develops an extended poetic invocation in which the speaker marvels at the west wind’s power, part two turns to the revolutionary vision the speaker wants the wind’s help to spread. Canto 4 marks the transition from invocation to vision. There, the speaker begins by summarizing the first three cantos and speculatively replacing the subjects of those cantos—earth, sky, sea—with themself (lines 43–45):

If I were a dead leaf thou mightest bear;
If I were a swift cloud to fly with thee;
A wave to pant beneath thy power

Essentially, the speaker wants to harness the power of the wind for their own purposes. In the rest of canto 4, the speaker reflects on the limitations of their own power while also praising the wind. This combination of humility and flattery sets up canto 5, where the speaker finally comes out with the request they’ve been meaning to make all along. That is, they ask the wind to aid them in spreading the revolutionary vision encapsulated in their poetry (lines 66–67):

Scatter, as from an unextinguish’d hearth
Ashes and sparks, my words among mankind!

Thus, the speaker’s elaborate invocation of the west wind in part one prepares the way for part two, where the speaker asks the wind to help disseminate their revolutionary vision.