If by dull rhymes our English must be chain'd,
And, like Andromeda, the Sonnet sweet
Fetter'd, in spire of pained loveliness;
Let us find out, if we must be constrain'd,
Sandals more interwoven and complete
To fit the naked foot of poesy;
Let us inspect the lyre, and weight the stress
Of every chord, and see what my be gain'd
By ear industrious, and attention meet:
Misers of sound and syllable, no less
Than Midas of his coinage, let us be
Jealous of dead leaves in the bay wreath crown;
So, if we may not let the Muse be free,
She will be bound with garlands of her own.
As I am currently 25, the age at which John Keats died, I cannot help but feel very unaccomplished. After all, he is remembered as one of the foremost Romantics, his deserved fame no doubt enhanced by the tragedy of his circumstances. I'm just some person who writes simple analyses of poetry online. That's okay, though. We don't all need to be Keats.
This poem is fundamentally an introspection on poetry, and how She, as personified by Keats, is bound by "dull rhymes." What Keats wants to do, since he feels unable to liberate poetry from rhyme entirely (though he does utilize slant rhyme in some places here) is use other techniques in order to make it not feel quite so constrained. "Sandals more interwoven and complete to fit the naked foot of poesy" are what Keats wants to create. To do so, by ear, he wants to listen closely to every part of a poem for musical content and beauty, not just the rhyme. Keats does this very thing all through the poem, with pleasing assonance and consonance throughout. It's a clever poem, and of course, beautiful, even if it is chained by "dull rhymes."