While most other poetic forms mandate a strict formality, the sonnet’s form is relatively simple: sixteen lines in ABAB quatrains, and then a singular rhyming couplet to tie it off. As a result, it is incredibly lyrical, and, in fact, Rafael Campo strings sixteen of them together (wherein each sonnet can be seen to represent one line) to form canciones, or “songs,” in Spanish. As a result, there is an inherent lightness to a sonnet that can not be seen in other forms that brings with it vivid imagery.
Despite its lightness, William Shakespeare’s “Sonnet 73” is rather dark: the speaker starts off by giving the reader permission to get a closer look at them, but only during the time when they’re starting to fade away, implying that there has been an emotional break between the speaker and the subject, almost like the speaker has wronged the subject, and as a result, the subject is showing the speaker their wounds and placing the blame upon them.
This contrast between what one would expect from the given form of a sonnet and the application that Shakespeare has given it heightens the tension between speaker and receiver, especially considering that Shakespeare has crafted this particular poem so that the speaker is directly addressing the reader.
This sadness is further foreshadowed in “[i]n me thou seest the twilight of such day,” implying that their happiness and joy has begun to fade, but also saying that the speaker’s perception is not reality- it is not that they are the “twilight of such day,” but instead that this is how the speaker sees the subject.
As a result, this poem is incredibly reminiscent of a ballad, with the speaker bidding their love goodbye, and wishing that it didn’t have to be so, while realizing that this is the natural course of events, it is “on the deathbed whereupon it must expire.
Shakespeare, William. “Sonnet 73” An Exaltation of Forms: Contemporary Poets Celebrate the Diversity of Their Art, Edited by Anne Finch and Kathrine Varnes, U. of Michigan Press, 2002, p 303.