Context: The poet hails the skylark not as a bird but as a "blithe Spirit," a symbol of pure joy which springs from earth toward heaven "And singing still dost soar, and soaring ever singest." It is "Like an unbodied joy whose race is just begun." Though the bird is hidden from the poet like a star in the daytime, he still hears its "shrill delight." He seeks comparisons for the voice which fills "All the earth and air. . . ." Drops from a rainbow cloud are less bright than the skylark's "rain of melody." The bird is like a poet "Singing hymns unbidden"; or "Like a highborn maiden" overflowing her bower "With music sweet as love"; or "Like a glow-worm golden" scattering its light "Among the flowers and grass"; or "Like a rose embowered" which with its scent "Makes faint with too much sweet" the winds that deflower it. The music of the skylark surpasses "All that ever was/ Joyous, and clear, and fresh. . . ." "Teach us, Sprite or Bird," pleads the poet, "What sweet thoughts are thine. . . ." He has never heard "a flood of rapture so divine." What are the sources of this joy? The singer in the sky cannot know languor, annoyance, or "love's sad satiety." Of death it "must deem/ Things more true and deep/ Than we mortals dream. . . ." We ever long for what we do not have, pain is mingled with our laughter, our sweetest songs are sad ones. Yet, says the poet, even if we "could scorn/ Hate, and pride, and fear," even if we were free from weeping, he knows not "how thy joy we ever should come near." The heavenly singer, "scorner of the ground," surpasses the sounds of earth, the treasures in books. "Teach me," the poet pleads again, "half the gladness/ That thy brain must know," and then the world will listen to his "harmonious madness" as he listens now. The most famous stanza of the poem is the eighteenth in which Shelley writes of the imperfections in earthly joys and music:
We look before and after,And pine for what is not:Our sincerest laughterWith some pain is fraught;Our sweetest songs are those that tell of saddest thought.