Although the poem consists of three sestets or six-line stanzas, Bishop’s “Shampoo” doesn’t have a tidy form. The lines are uneven, with some lines (Line 8, for example) looking clipped and other lines (Lines 5 and 6, for example) jutting out. The varying line length reinforces the “explosions” (Line 1) and “shocks” (Line 3) of the poem. Shampooing is a galvanizing exercise for the speaker and their friend. The mix of long and short lines emphasizes how washing the hair represents a joyous jolt for the speaker. As with the “tin basin” (Line 17), the speaker batters or beats back some of the lines while letting other lines come forward.

Conversely, the form represents an order that advances the “amenable” (Line 12) environment of the speaker and their friend. Aside from the three sestets, Bishop employs the same rhyme scheme in all three stanzas, with Lines 1 and 3, Lines 2 and 5, and Lines 4 and 6 rhyming in each respective stanza. The rhymes create a subtle melody that mirrors the pleasantness the speaker obtains from washing their friend’s hair. The rhymes also bolster the idea of partners or pairs—each line has another line to rhyme with, and the speaker has someone else to be with: Their “dear friend” (Line 9).