The form of "Bells" includes increasingly longer stanzas that match the speaker's emotional turmoil, reflecting an inner turmoil about death. Each of the stanzas becomes increasingly longer as the speaker's sense of frenzy intensifies. The first stanza is the most lucid, and the descriptions of the bells are pleasant. The melody is "merry," and the bells keep time against a star-sprinkled nighttime sky. The second stanza is a bit longer as hints of panic are interjected into the previously peaceful sounds of bells. The turtle dove "gloats" and the rapture "impels" as the bells continue ringing. In the third stanza, the speaker's emotions reach a climactic frenzy as the bells become a "tale of terror." They are "desperate" and swell in "anger," no longer bringing the speaker any sense of promise or peace. In the final and longest stanza, the speaker collapses into repetition and a singular focus as all sense of hope disappears. The constancy of the bells' ringing becomes the only thing that matters, and their sound is described as "moaning and ... groaning."
It's also important to note the way some lines are quite short, bringing a particular focus to those lines:
Out of tune ...
Of despair ...
These short lines support themes of isolation and despair, visual reminders of the speaker's sense of solitude. The fourth and most dismal stanza lacks the longer and flowing lines found earlier in the poem. For example, the first stanza contains this line:
What a world of merriment their melody foretells!
The loss of these longer lines reflects a growing feeling of hopelessness as the poem progresses.