Moonlight works a silent alchemy here. Shelley doesn’t so much describe the moon as trace how beauty seeps into the things around it, changing them from the inside out. A violet gazes at the sky until its own color deepens to match. A lifeless mist draped over a mountain glows purple like a gem when sunset touches the snow. Even the empty wind wraps itself around a strain of music until it too sings. The speaker’s tone is hushed, almost reverent—he delights in how the ordinary opens itself to loveliness. By the final image, something dark and hollow basks in what is beautiful and becomes “full of light and love.” The mood is dreamy and buoyant, a slow dissolve from emptiness into radiance. It feels as if the whole world, if only we linger long enough, will lean toward grace.
Variation of the Song of the Moon — Summary
("PROMETHEUS UNBOUND", ACT 4.)
As a violet's gentle eye Gazes on the azure sky Until its hue grows like what it beholds; As a gray and empty mist Lies like solid amethyst Over the western mountain it enfolds, When the sunset sleeps Upon its snow; As a strain of sweetest sound Wraps itself the wind around Until the voiceless wind be music too; As aught dark, vain, and dull, Basking in what is beautiful, Is full of light and love--