The three-part-line in poetry
Most often, the line is a complete unit of sense in poetry. Open Shakespeare anywhere, or the Oxford Book of English Verse, and you find whole uninterrupted lines.
Come live with me and be my love, And we will all the pleasures prove.
This is the classic verse line. Shakespeare is noted for his work here:
Sometimes too hot the eye of heaven shines.
Emily Dickinson, using slightly shorter lines, also excels at these sorts of complete, uninterrupted lines.
Hope is the thing with feathers. The soul selects her own society. Because I could not stop for Death...
Often, a line is split in half. We call that caesura.
Many a night I saw the Pleiads, rising through the mellow shade.
Those halves could be split up into two separate shorter lines, unlike this example:
Many a night from yonder ivied casement, ere I went to rest...
That is still a caesura to denote syntax. But it is a two-part line. It is no longer our single, classical line. The poet uses syntax to meddle with its smooth, linear progression.
Two-part lines work well at the ends of stanzas, like in Housman.
Into my heart an air that kills From yon far country blows: What are those blue remembered hills, What spires, what farms are those?
The break there is rhetorical. Two-part lines interact with single lines in drama effectively. Here are two, two-part lines, building the the tension toward the enjambement at the end of the second line to deliver the implied or expected meaning.
Give me the map there.—Know that we have divided In three our kingdom, and ’tis our fast intent To shake all cares and business from our age...
For an actor, these two-part lines are a clear indiction of how to be a total arse, as Lear is being. The first half line is a command: the line then switches attention to a second group of people in the room, from servant to son-in-laws. The line breaks where Lear's attention breaks.
This principle of lines being made of parts means we can often see a three-part-line in verse, although I have never seen this explicated anywhere. These sorts of lines are smuggled in all over poetry, but I don't think they are properly theorised or analysed.
How fresh, O Lord, how sweet and clear.
Three distinct parts to the line. The adverbial fragment, the vocative, and the noun phrase (which is a hendiadys).
Shakespeare, of course, uses these in drama to show the action of a mood changing as location changes, as with this line from Lear.
Here's the place: stand still: how fearful.
Sometimes a three part line is a simple repetition, so that the three parts are metrically identical. The chanting effect heightens the sense of despair in this example.
Tomorrow and tomorrow and tomorrow
Tennyson uses the same technique:
Break, break, break
And Keats learned from Shakespeare how three-part-lines can invoke atmosphere, which he does here in a similar mode to the Lear example above:
The owl, for all his feathers, was-a-cold.
Modern poets use three-part-lines all the time, but following Eliot they break them up into smaller, shorter lines. I have a hunch this might be a big part of what separates pre-modernist and post-modernist poetry.
Here's Eliot breaking a three-part-line into two shorter lines.
I smile, of course, And go on drinking my tea
Eliot could write single lines as well as anybody, for reference:
The burnt out ends of smoky days
But his method of breaking lines up is fundamental to much modern writing. Watch Elizabeth Bishop do it in these lines from The Moose:
bumblebees creep inside the foxgloves and evening commences
Or this haiku translation by Anthony Thwaite:
Clouds now and then Giving men relief From moon viewing
The modern writers who stuck more closely to iambic forms, like Robert Lowell, produce some of the best three-part-lines:
raw-jawed, weak-fleshed there, stopped by ten steps of the roaring ladder
Auden could manage the same thing in fewer syllables:
Cold, impossible, ahead Lifts the mountains lonely head
And Dylan Thomas uses the three-part-line to open his third stanza with uncertainty, delayed meaning, perhaps a sense of confusion akin to the mental calamity of dying:
Good men, the last wave by, crying how bright Their frail deeds might have danced in a green bay Rage, rage against the dying of the light.
Seamus Heaney knows how to use this technique to deliver concise narrative summary, cascading verbs through the three part structure:
Apollo turned and twisted His spurs at her breast, gave her her head, then reined in her spasms.
This is the sort of usage Heaney gets a lot of mileage out of to poetise the everyday. Here is a three-part-line, a two-part-line and another three-part-line. The effect is to expand the action in shuttering images, like in a movie, then to slow the action down, and finally to start ordering the details of the environment.
Roof it again. Batten down. Dig in. Drink out of tin. Know the scullery cold, A latch, a door bar, forked tongs and a grate.
The last noun phrase means this remains as a three-part-line. The third line breaks from action to description. The technique has got Heaney from repairing the roofing to sitting by the fireplace in twenty-nine syllables.
This perspective shifting happens more readily in three-part lines, and this is how Heaney keeps his domestic, earthy tone of voice. The three-part lines lets him juxtapose vernacular words without prettifying them with too much poetry:
Hunkerings, tensings, pressures of the thumb
Making gerunds is how he achieves rhetoric from daily language, a clever trick. Three-part-lines, arranging those words so that they evolve from the more to less obscure, from less to more ordinary, are how he turns that into poetic form.