Diction refers to the words one chooses to use when speaking or writing. When evaluating the diction of Elizabeth Bishop’s poem “I Am In Need of Music”, consider the first word of the poem: it’s “I.” Based off of one word, it’s possible to argue that Bishop is employing a personal diction. Her word choice conveys the intimate, visceral nature of the poem.
Now, think about “need.” This term should make Bishop’s audience realize that there’s an urgent issue at hand. The speaker doesn’t “prefer” music. The speaker wouldn’t “mind” some music. The speaker has to have music to make her feel better. The diction demonstrates this critical situation to the audience.
Moving on to the rest of the poem, consider how the diction supplies a melody that enhances the musical theme of the poem. Bishop uses words that, when put together, form a harmonious sound.
Take a look at the first line of the second stanza. There’s seven words, and three of them start with the letter m. The arrangement of words links to syntax. Bishop is organizing words based on how they sound and the letters they start with in order to reinforce the melodious tone of her poem for her audience.
As for other literary devices, one might want to think about how alliteration adds to the pleasant sounds of the poem. One could also talk about how the poem's images relate to the calming properties of music.