Prometheus Unbound is quite stylistically diverse, written as lyric poetry in both blank verse (unrhymed iambic pentameter) and rhymed sequences, often in couplet form. Blank verse is the standard, as is true of most traditional epic poetic dramas. Shelley will often deviate from this standard, however, particularly in passages where members of the chorus or spirits must speak. Take this passage from the first Semichorus towards the end of Act 1:
Drops of bloody agony flow
From his white and quivering brow.
Grant a little respite now—
See! a disenchanted nation
Springs like day from desolation;
This passage is written in tetrameter, rather than pentameter—simply meaning that each line contains eight syllables, rather than ten. Shelley will often set up a loose metrical structure like this and deviate from it: clearly, the first two lines of this excerpt are not iambic tetrameter, though they are closer to it than the preceding three. The last couplet of this excerpt even appears to invert the traditional iambic metrical structure, opting instead for something that sounds trochaic (beginning with a stressed syllable, as opposed to an unstressed one).
Shelley was, first and foremost, a poet; one can see this coming through clearly in his writing style, which features a great deal of figurative language—much greater than average, even for a traditional drama.
