A poem’s tone is its overall mood, which is the product of a few literary forces working in union. The meter, rhythm and rhyme scheme of a poem form part of its mood, as do diction (the choice of words) and language. A poet may also use refrain in a poem -- a set of lines that repeat, such as in Tennyson’s “Charge of the Light Brigade,” similar to the chorus in a song. All of these features together describe tone, and each may illuminate the two meanings of the poem you wish to analyze.
Poems usually have a meter that you can measure and explain in an essay. If all of the lines of a poem contain, for example, ten syllables and each line has a stress pattern of alternating between unstressed and stressed syllables, you can describe the poem as having “iambic pentameter” -- the type of meter Shakespeare often used. Meter creates a way of reading the poem aloud, which forms the tone of the poem. Shakespeare was an ace at double entendre, dirty jokes hidden among his iambs. On first reading, lines like this from "A Midsummer Night’s Dream" may sound like pure description: “But I might see Cupid’s fiery shaft / Quenched in the chaste beams of the watery moon.". Read more closely, and there’s some sexual imagery hidden in there, though perhaps not too cleverly hidden. The meter doesn’t always indicate a serious tone; meter can mask double-meaning, and your analysis should note that.
Like meter, the rhythm of a poem creates a particular mood when read aloud, but the rhythm is more subjective than meter, which follows pronunciation rules. Rhythm is in the mouth of the reader. University of North Carolina’s Writing Center uses the example of Keats’ “Ode to Melancholy,” which begins “No, no, go not to Lethe, neither twist." The line is iambic pentameter, but could be read by stressing the first four or five syllables to create a sense of urgency. Read one way, the poem is melancholic; read another, it’s without sadness, only urgent. Tension between the way a poem appears and the way you read it creates mood, which affects the tone. During your analysis, look at these points in a poem to explain that there’s an opportunity to read a particular line two different ways.
Repetition and Word Choice
Repetition in a poem brings the reader back to a central image or expression. In Tennyson’s “Charge of the Light Brigade,” each stanza ends with the words “six hundred,” though the fate of the six hundred changes each time the poet comes back to it. While the poem begins and ends by praising the valor of the six hundred soldiers, it tells of their slaughter through the middle. The heroic refrain becomes something different as the poem advances, changing the meaning. In an analysis, look for repeated words and phrases and explain how their meaning changes throughout the poem.