Dissonance is a tool that relies on including jarring, unpleasantly-sounding, and unexpected words and phrases in literary works. In its essence, this device allows writers to set the tone of a piece and create the feeling of disharmony and chaos. Consonance is closely related to assonance and cacophony, as they also deal with sound manipulations that affect the reader’s perception of the work.

The term itself derived from the Latin language and was borrowed from French. Its original form was “dissono”, which is translated as “to sound uneven”, “discord”. Initially, this term was used only in relation to musical pieces, before spreading to literary sciences, once dissonance began to be actively employed by poets.

Due to their related meaning, dissonance is frequently confused with assonance. Even though both tools serve the purpose of setting the mood for a poem or story, they employ different means to achieve it. Thus, assonance relies on including similarly sounding syllables and words and placing them near each other. This allows authors to establish rhythm and rhyme, while also creating the feeling of harmony in a piece, which is the opposite effect of dissonance.

Another term commonly mistaken for dissonance is consonance. The latter is mostly employed in poetic works and functions similarly to assonance. The goal of this device is to make a text seem more visually and acoustically pleasing to the reader. This purpose is achieved by adding words that either begin with the same consonant sound or share several consonants while being placed near each other.

In contrast to the two terms discussed above, dissonance serves to establish the feeling of unpleasantness in a poem or story, leading to the reader experiencing discomfort. This tool also allows enhancing the atmosphere of a work and deepening the emotional impact of a specific event, thought, or dialogue line. 

Oftentimes, dissonance is employed to describe turbulent and uneasy situations and can be found in thriller and horror stories as a means to build up the tension. On the other hand, this tool can also be implemented to achieve a comedic effect and entertain the reader with wordplay, an unexpected turn of phrase, etc.

Dissonance is most commonly featured in works written in verse, as poetry heavily relies on the sounds the author uses. Thus, poets employ dissonance, along with other tools, to establish a rhythm, create or destroy rhyme, emphasize certain thoughts and images, and help convey the main idea of a poem.

This literary tool can also be found in prose works, as it allows authors to set the mood of the story and make readers feel discomfort or sadness from reading certain sentences. Ordinarily, a sequence of jarring words can surprise readers and leave them in shock, if it’s accompanied by appropriate information. Alternatively, dissonance can be included in dialogues between characters to highlight the importance of a specific thought or to establish a hero as an unpleasant person.

In most cases, this device isn’t placed throughout the work but rather in specific moments that require additional attention and analysis on the part of the reader. Such situations usually include events or emotional confessions that are integral to the understanding of a piece.

Dissonance is also oftentimes implemented in drama. Since such works are written primarily to be acted on stage, the employment of harsh-sounding words can have an even more powerful effect on live audience, as, unlike readers, they hear them being pronounced.

Dissonance isn’t limited to literary works, as this term is also used in music theory and psychology. Due to the eye-catching nature of unpleasant and jarring words, they are also found in songs and advertisements. Furthermore, dissonance commonly occurs in mundane situations, as the combination of a yelling individual and someone swearing has the same effect on the listener.

There are plenty of examples of poets using this literary tool, but it’s especially commonly featured in the works of Walt Whitman. For instance, the poem “To a Locomotive in Winter” features several lines that have jarring words such as: “Law of thyself complete, thine own track firmly holding (no sweetness debonair of tearful harp or glib piano thine…)”. In this case, the author employs dissonance to set the mood of the poem and recreate the general sounding and feel of a locomotive machine.

Another example of a poet using this device can be found in the “Player Piano” by John Updike. The writer uses phrases like “My stick fingers click with a snicker” and “never my numb plunker fumbles” to convey the mechanical nature of the machine that plays music. Despite the fact that it performs its task efficiently, the general concept of music being created by a machine is unnatural, and that idea is reflected in the author’s word choice and the general mood of the poem.