Although Byron was inspired by a particular woman, Anne Beatrix Wilmot, his cousin’s wife, in his composition of “She Walk in Beauty,” the poem is more than a portrait of a particular beautiful woman. The subject of the poem, who remains unnamed, is portrayed in broad terms, with the only identifiable features being her “raven tress[es]” and her serene, beneficent temperament. 

Indeed, as is typical of Byron’s Romantic poetics, the subject is transformed by the speaker’s imagination. Thus, while the poem is occasioned by an external figure, it is the movement of the speaker’s mind that takes center stage. For example, in the first line, the subject’s presence is immediately subsumed by the speaker’s metaphorical and imaginative flight to a “cloudless” and “starry” night sky. In the speaker’s subsequent physical descriptions of the subject, his own imagination, equipped with the power of metaphor, often overshadows the subject herself. To say that her “nameless grace,” the result of a perfect harmony between darkness and light, “waves in every raven tress” and “softly lightens o’er her face” is to present a densely figurative structure. This style and approach is very much in keeping with the tradition of English Romantic poetry, of which Byron was a major practitioner. Other typical Romantic elements in the poem include its use of imagery drawn from the natural world and its keen interest in sublimity and beauty.

The poem is composed of three stanzas, with each stanza consisting of six lines of iambic tetrameter. That is, each line contains four iambs, rhythmic feet consisting of an unstressed syllable followed by a stressed syllable. The rhyme scheme is ABABAB. Given its meter and rhyme scheme, one could argue that the poem’s form is a variation on the ballad, but whereas a typical ballad consists of quatrains, “She Walks in Beauty” consists of sestets. These formal qualities combine to give the poem a playful, song-like structure and tone. This is in keeping with the volume in which the poem was published, Hebrew Melodies, which was conceived as a set of lyrics to be accompanied by music. More importantly, the poem’s form is in keeping with its subject matter. “She Walks in Beauty” is fundamentally a poem of celebration and praise, and Byron’s tetrameter rhythms lend it an appropriately joyful air.

Byron further contributes to the poem’s rich musicality through the ample use of alliteration, consonance, and assonance. The second line contains two separate alliterative phrases, “cloudless climes and starry skies,” conveying the speaker’s feelings of enchantment. There is some playfully percussive consonance on the theme of d in the phrase “gaudy day denies,” as well as instances of assonance in “nameless grace” and in  “waves” and “raven,” with both pairs relying on repeated long a sounds.

Another important device Byron uses is parallelism. In numerous lines, Byron creates a sense of balance at the level of syntax and rhetoric in order to convey the balance the speaker sees in the beautiful woman he described. Such parallelism can be seen in lines such as “One shade the more, one ray the less,” “And on that cheek, and o’er that brow,” and “The smiles that win, the tints that glow.” In each case, Byron brings two rhythmically and syntactically equivalent phrases together, thus imitating the balance of contrasts embodied by the woman in whom the “best of dark and bright / Meet.” This control of syntax is an excellent example of form mirroring content.

The poem’s central symbolic structure is built on the opposition between darkness and light. Byron establishes these symbols by introducing the metaphor of “starry skies,” an...