The poem begins with the narrator describing the beauty of the nightingale's song. He says that the nightingale's song is "so sweet, so shrill, so pleasing" that it "pierces the heart." He then goes on to compare the nightingale's song to the beauty of a woman. He says that the nightingale's song is "like the sound of a lute or viol" and that it is "as sweet as the smell of flowers."
The narrator then begins to reflect on the nature of love and loss. He says that love is "a joy of heaven" but that it is also "a pain of hell." He then goes on to say that love is "a torment" and that it is "a pleasure." He concludes by saying that love is "a mystery."
The poem Nightingale by Sir Philip Sidney is a beautiful and complex poem that explores the nature of love and loss. The poem is full of imagery and symbolism, and it is a testament to Sidney's skill as a poet.