Keats' thesis is that "the poetry of the earth is never dead," and most people read the poem as a celebration of the enduring beauty of nature. However, upon closer inspection, it is clear that the poem is concerned specifically with sound. It is the grasshopper's voice that "takes the lead" in celebrating summer after the birds have fallen silent; similarly, it is the cricket's song that "in warmth increasing ever" enlivens the otherwise silent winter night. Of course, there is a direct connection between the songs of these insects and Keats' own "song," his poetry, which he hopes will persist in the same way.
Your essay could state this theme in the introduction, then consider, in separate paragraphs:
- the imagery of silence (the hot fields, the frosty night)
- the voices of the insects, and singing as an expression of joy
- the idea of persistence, and images that suggest the permanence of nature
I would end by considering carefully the final two lines of the poem: How does the drowsiness of the poet, who mistakes the song of the cricket for that of the grasshopper, relate to the idea of the "never dead" poetry of the earth? How does this final image suggest, perhaps, a poetic process?