Seven short lines, and almost nothing in them stays put. "Summer Sequence" begins with a celestial image and ends, by way of a slippery chain of sounds, at an old proverb about people in glass houses throwing stones. The poem's real subject is not summer or stars but the way language moves: how one word, once spoken, drags the next one behind it.
Start with the first two lines, "Summer stars / summarize." The words "summer," "stars" and "summarize" are bound together by the repeated s and m, and the verb is a small joke: stars don't summarize anything, yet the sound insists that they should. The verb gives the night sky a faintly intellectual job, as if the stars were condensing the whole season into a few points of light. Something plain and visual has been turned into something verbal, and the poem has announced its method. Sound will lead, and sense will have to catch up.
The next lines make the method visible. "And some are glass" pivots on "some," a word that quietly echoes "summer" and "summarize" while the meaning shifts: some of the stars, apparently, are made of glass. Then "glass eyes" arrives, and the image changes character completely. Stars become eyes, and artificial eyes at that, the sort made for a doll or a statue, bright and seeing nothing. "Isinglass" follows, a word that is surprisingly rich for a poem this spare. It names a translucent substance, historically used as a kind of window material and also in clarifying liquids, and its sound neatly contains "eyes" and "glass" at once. It works almost like a hinge: the poet gets from "glass eyes" to the next line by finding a word that holds both halves together. Whether or not a reader knows what isinglass is, the word glitters on the tongue, and the poem seems to know it.
Then comes "eyes in glass houses," which is the moment the sequence tips over. Glass has been a material, a kind of eye, a substance with a strange name; now it becomes architecture, and the stars are no longer overhead but housed, exposed, watched. The final line, "throwing stones," completes the proverb without needing to quote it. The ending is the point at which the poem's drift of association collides with a piece of ready-made wisdom about vulnerability and hypocrisy, and the effect is slightly ominous. The glittering stars of the opening have become fragile objects that could shatter.
Formally, the poem is a single sentence-like stream with no punctuation beyond a closing full stop, so the lines run into each other like the associations they record. There is no regular meter or rhyme scheme, but the poem is thick with internal music: the sibilants of the opening, the hard repeated "glass" (four appearances in six lines, if you count the compound), the echo of "eyes" and "isinglass." Repetition does the work that rhyme would normally do, tying the lines together by recurrence instead of by end-sounds. The word "glass" is the real engine of the poem, turning over and showing a different face each time: material, organ, window, house.
What makes the poem worth reading is how much it does in so little space. It shows that a poem can proceed by sound as well as by argument, following the pull of words toward one another until an unexpected meaning surfaces. Cold, bright, brittle and a little menacing, the poem leaves a single impression: that the night sky and our own habits of speech are both made of fragile material, and that it takes only a thrown stone, or a stray association, to change everything.