Poem found here: "Belfast Tune" by Joseph Brodsky
The poem is in quatrains with an alternating rhyme scheme (abab). And there is a sense of musicality within the poem, but the content within the poem has broader implications.
But, with the beginning of a tune, there's something specific, a girl:
Here's a girl from a dangerous town
She crops her dark hair short
so that less of her has to frown
when someone gets hurt.
Note the how ambiguous the town is described versus the specific intent of the girl. Also the girl is reacting to the danger -- of someone getting hurt. And note that the specific detail of the cropped hair not to hide but to see.
She folds her memories like a parachute.
Dropped, she collects the peat
and cooks her veggies at home: they shoot
here where they eat.
The image of the parachute kind of downplays the gravity of the violence in the line "they shoot / here where they eat" since the metaphor is so vivid of the unstated expanse to the folding of something so large meant to slow a descent to something so domicile, but violent.
Ah there's more sky in these parts than, say,
ground. Hence her voice's pitch,
and her stares stains your retina like a gray
bulb when you switch
So here's the interesting thing about this stanza is that there's the introduction of a third party that judges her voice. Furthermore, the metaphor at the beginning could represent a crash down to earth -- the expanse versus limited land. If these ideas are intertwined than what we see is limited what we imagine of the girl is expansive not only to the "you" but also to the "I" that comes in at the end.
hemispheres, and her knee-length quilt
skirt's cut to catch the squall,
I dream of her either loved or killed
because the town's to small.
So there's the physical memory of her "knee length quilt skirt" that leads to a metaphor of the metaphorical squall in the town. But the last part, the abrupt intrusion of the speaker's thoughts on what will happen to her takes away the momentum of the metaphor and the girl. By intruding, the speaker wants to make a stand to say "this is what we should worry about" small town girl being loved or killed.