He would declare and could himself believe
That the birds there in all the garden round
From having heard the daylong voice of Eve
Had added to their own an oversound,
Her tone of meaning but without the words.
Admittedly an eloquence so soft
Could only have had an influence on birds
When call or laughter carried it aloft.
Be that as it may be, she was in their song.
Moreover her voice upon their voices crossed
Had now persisted in the woods so long
That probably it never would be lost.
Never again would birds' song be the same.
And to do that to birds was why she came.
Robert Frost, The Poetry of Robert Frost, ed. Edward Connery Lathem, Henry Holt & Co., 1951.