What’s Up With the Title?
"To Autumn" seems to be missing a key word when compared to Keats's other Great Odes: the word "ode." You would expect the title to be, "Ode to Autumn," but maybe Keats felt confident that he had this whole ode thing down and could just use a shorthand.
However, "To Autumn" seems to change the meaning, as well. It sounds like a dedication you might read in the front of a book: "To Mom and Dad," "To My Kindergarten Teacher, For Not Failing Me At Finger-Painting," "To Autumn." Or Keats could merely be helping us understand whom the speaker is addressing. Otherwise, when he asks, "Who hath not seen thee?" in the second stanza, we might think he had forgotten to introduce a character. Whatever your explanation, "To Autumn" stands out as a title among Keats's odes.