If by dull rhymes our English must be chained,
And, like Andromeda, the Sonnet sweet
Fettered, in spite of painéd loveliness;
Let us find out, if we must be constrained,
Sandals more interwoven and complete
To fit the naked foot of poesy;
Let us inspect the lyre, and weigh the stress
Of every chord, and see what may be gained
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.
There is a theme in English romantic sonnets of the "contraintedness" of the form. There is this one by Keats and some others by WW: "Nuns fret not ..." The idea that the sonnet is narrow, a constraint. Shakespeare and Donne (or Milton) would not have thought about it that way. I've italicized some words that emphasize some negative aspects.
See Frost's "The Silken Tent," which continues the theme of ties, and bondage.