Another major idea or theme of "Ode to the West Wind" is that a poet's ideas can be blown all over the earth the way the wind blows autumn leaves. The leaves on a tree remind the poet of leaves of paper on which he writes his verses.
In the last verse, the poet addresses the wind, asking if he, the poet, can become its "lyre" or the instrument the wind plays. The poet desires to become one with the spirit of the wind. "Be thou [you] me," he implores. Here, he continues to convey the idea that his thoughts can be sent all over.
The poet understands the wind as a universal song that he can join. He notes the wind's "mighty harmonies." Finally, he imagines that he and the wind can come together so the wind becomes his "trumpet" and spreads his words.
In this, the poet expresses his deep, fervent desire not just to write poetry or experience rebirth, but also to have his thoughts widely known through his words.