A skylark soars into the sky singing happily. As it flies upward, the clouds of evening make it invisible, but its song enables the poet to follow its flight. All the earth and air is filled with its song. The unseen but still singing skylark is compared to a poet composing, a maiden in love, a glowworm throwing out its beams of light, a rose in bloom diffusing its scent, and the sound of rain on twinkling grass. Songs sung in praise of love or wine or music played for a wedding or a celebration cannot compare in loveliness with the song of the skylark.
What accounts for the happiness of the song of the skylark? It is free from all that gives pain to man. It knows what lies beyond death and has no fear. Even if man freed himself from hate, pride, and fear, man's joy would not equal the skylark's. The secret of its capacity to sing so happily would be an incomparable gift for the poet. If the skylark could communicate to Shelley half its happiness, then he would write poetry that the world would read as joyfully as he is listening to the song of the bird.
Mary Shelley wrote about "The Skylark": "In the Spring we spent a week or two near Leghorn . . . It was on a beautiful summer evening while wandering among the lanes whose myrtle hedges were the bowers of the fire-flies, that we heard the carolling of the skylark." Like the "Ode to the West Wind," "The Skylark" was inspired by a specific experience, but Shelley's interest in the skylark is not that of the bird lover or the bird watcher. What he is fascinated by is the happiness that, for him, is present in the song of the bird. He doesn't say that he sees the bird, but it would seem that he has watched it leave the ground and disappear into the bright clouds above the setting sun, for he says that "the pale purple even / Melts around thy flight." The color of the bird, its flight pattern, the quality of sound which distinguishes its song from that of other birds — in short, the individuality of the bird — the reader learns nothing about from reading "To a Skylark." Shelley has converted the bird or, specifically, the bird's song into a symbol of happiness. The poem, then, is not so much about a skylark as it is about happiness. The singing bird is personified as a "blithe" or happy spirit in the first line of the poem.
Shelley pursues two main lines of thought in the poem. The first is an effort to determine to his own satisfaction with what the singing bird is comparable. This is a relatively unimportant matter. The reader merely learns what the singing skylark brings to Shelley's mind in the way of similes. The birdsong is like a poet composing, a maiden making music, a glowworm scattering light, and a rose diffusing its perfume. The similes have in common the fact that all four are, like the now unseen skylark, out of sight or not easily seen.
The second line of thought is central to the poem. What, Shelley asks, is the secret that accounts for the skylark's happiness, manifested in its song?
What objects are the fountains
Of thy happy strain?
What fields, or waves, or mountains?
What shapes of sky or plain?
What love of thine own kind? what ignorance of pain?
These questions lead him to an analysis of the human condition. Man knows pain, experiences weariness, annoyance, and love's satiety. He is plagued by hate and pride and fear. He cannot escape his past, thoughts of the future cause him worry, he longs for what does not exist, and his laughter is mixed with sorrow. He dreads death. The skylark, on the other hand, Shelley fancies, "of death must deem / Things more true and deep / Than we mortals dream." Therefore the skylark has no fear of death.
Shelley, in personifying the skylark, has created a myth, just as in "Ode to the West Wind" and "The Cloud." He has endowed his skylark with mind ("Teach us, Sprite or Bird, / What sweet thoughts are thine"). The skylark is happy because it knows only what makes it happy. It has a decided advantage over human beings, who know both what makes them happy and what makes them unhappy. They fear death because they are ignorant of what lies beyond death, among other reasons. The skylark knows what lies beyond death, and the nature of what it knows banishes its fear of death. It is no wonder that it is incomparably happy.
Shelley knows that his skylark is merely a bird with a song that, to the human ear, sounds like a happy song. He is indulging in fancy and has no intention whatever of deceiving the reader or himself. The exquisite happiness that his ear has heard in the song of the nightingale has carried him away. In the last stanza of the poem he appeals to the creature of his imagination to teach him half the gladness "that thy brain must know." Happiness is the secret of the lovely song of the skylark; if Shelley possessed only half of the "gladness" of the skylark, he could write poetry that the world would read with the same rapt attention he is giving to the song of the skylark that his ears hear.