Metaphors help to communicate the poem's philosophy on change and loss.
The poem's central extended metaphor compares change (and especially "dissolution," or disintegration) to music. The awe-inspiring "notes" of change, the speaker tells readers, rise and fall from "low to high" and "high to low" again—an idea that blends two metaphors into one:
- That movement from "low to high" and back again suggests an evolving melody.
- It also reminds readers that everything, from the lowliest bug to the highest tower, is part of this change: living and dying, rising and falling.
That's why the melody of change isn't just "musical," but "melancholy": there's certainly beauty in this cycle of life and death, the speaker suggests, but people have to accept the sadness of loss in order to hear the harmony of the "chime."
One of the poem's later metaphors returns to the idea that even the mightiest things fall from "high to low." Describing a once-"sublime" tower now fallen into decay, the speaker imagines it wearing a "crown of weeds"—an image that reminds readers that all crowns (that is, all worldly powers, speaking metonymically) are in reality frail and temporary.
All it takes is a "casual shout," the speaker goes on, to "br[eak]" the silence of stasis. Using the image of a shout breaking the "silent air," the speaker again reminds readers that change inevitably brings destruction with it.
It takes a keen listener, these metaphors suggest, to hear the music of grief and change—to find beauty in life's inevitable losses.