When we think of music, we often think of the way words are set to a particular rhythm and the way tones and pitch convey a message that produces an emotional response. In poetry, writers don't have quite the same tools; they can't, for example, rely on a rising and falling volume or the accompaniment of instruments to help create the music of the poem. Instead, poets rely on other techniques to craft the musical language often found in poetry, including things like meter, repetition, alliteration, assonance, consonance, structure, and rhyme.
In "Hawk Roosting," the poem is created to show the first person perspective of a hawk as he describes his view of the world. The musicality of the poem reflects this stance. It is both carefully laid out and steady, the lines short and heavily punctuated. The reading is thus slow, much like the patience of the hawk as he awaits the perfect creature to kill. The consonance often focuses on hard sounds, like this line:
My feet are locked upon the rough bark.
Although the hard r sound is dominant in this line, the hard k sound is also repeated.
The speaker also uses repetition within lines to focus on specific attributes of the hawk:
Between my hooked head and hooked feet:
This repetition creates an image of the hawk and shows him to be both dangerous and physically impressive.
The meter of the poem varies from line to line, which adds to the unpredictability of the hawk's nature. He is a formidable predator, and he relies on both his stealth and his ability to sneak up on his prey to take a
flight ... direct
through the bones of the living.
The musicality of "Hawk Roosting" isn't an easy cadence with a neat meter, and that is intentional to reflect the power and nature of the predator whose voice is heard in this poem.