Robert Pinsky, The Sounds of Poetry:
The theory of this guide is that poetry is a vocal, which is to say a bodily, art. The medium of poetry is a human body: the column of air inside the chest, shaped into signifying sounds in the larynx and the mouth. In this sense, poetry is just as physical or bodily an art as dancing.
Moreover, there is a special intimacy to poetry because, in this idea of the art, the medium is not an expert’s body, as when one goes to the ballet: in poetry, the medium is the audience’s body. When I say to myself a poem by Emily Dickinson or George Herbert, the artist’s medium is my breath. The reader’s breath and hearing embody the poet’s words. This makes the art physical, intimate, vocal, and individual.
… I hope to focus on the way an extraordinary system of grunts and mouth-noises evolved by the human primate has been used as the material of art. … I presume that the technology of poetry, using the human body as its medium, evolved for specific uses: to hold things in memory, both within and beyond the individual life span; to achieve intensity and sensuous appeal; to express feelings and ideas rapidly and memorably. To share those feelings and ideas with companions, and also with the dead and with those to come after us.