In this poem, Pound at once courts the longstanding tradition of iambic pentameter and breaks with it. Recall that iambic pentameter refers to a metrical form where each line consists of five iambs, each of which is made of one unstressed and one stressed syllable. (Think of words like “se-rene” and “be-low.”) Iambic pentameter has been a staple of English-language verse since the sixteenth century, when it first came into prominent use. Part of what made iambic pentameter so popular was the way it avoided the sing-song rhythms of shorter lines. By extending the poetic line to five iambic feet, poets found a more natural-sounding rhythm that conveyed a sense of seriousness and even nobility. For this reason, iambic pentameter became the go-to meter for the most significant poets in the language, from John Milton and William Shakespeare to William Wordsworth and Elizabeth Barret Browning.

Pound understood well the dominance of iambic pentameter, but he also wanted to break with established poetic forms. In reading “In a Station of the Metro,” we can see how he flirts with iambic rhythm, but ultimately dispenses with it:

     The app- | a-ri- | tion of | these fa- |ces in | the crowd:
     Pe-tals | on a wet, | black bough.

The first line consists entirely of iambs. That said, some might argue that the line subtly falls out of iambic rhythm in the third foot. Indeed, instead of being scanned as an iamb, the third foot could be read as a pyrrhic, which is a metrical foot that consists of two unstressed syllables. Regardless, what’s clear is that even as Pound suggests iambic meter in the first line, the rhythmic pulse is weak. Furthermore, the line is one foot longer than the traditional pentameter line. The diminished rhythmic pulse and the slightly longer line may suggest that iambic pentameter, no longer in its prime, has officially overstayed its welcome. By contrast, the second line breaks from iambic rhythm entirely. This line consists of a trochee (stressed–unstressed), an anapest (unstressed–unstressed–stressed), and a spondee (stressedstressed). With this line, Pound altogether abandons regular meter, preferring to find a rhythm more suitable for the specific image he wants to evoke.