Poems, being what they are (brief moments in time), need to catch the reader in its first few lines (the fourth at the very outset). If the reader hasn't seen or felt something new, striking, startling, surprising, charming, enticing, she isn't wont to keep reading. She'll turn to the next poem.
"The line cannot go against the breathing-rhythm of the poet." (The Life of Poetry, p. 117)
"If a good line contradicts a principle one has formulated, then the principle, by which I mean a kind of working idea, should be disregarded or amended." (The Sounds of Poetry, p. 7)
"[T]he poem is something one hears aloud, and the poem in print is a notation designed to make what one hears as clearly apprehensible as possible." (The Sounds of Poetry, p. 43)
"[T]hough the typography is notation for what we hear, the long lines do tell us that the pauses marking off elements of different lengths are part of a larger cadence or symmetry[.]" (The Sounds of Poetry, pp. 108-09)
"It is this 'plot line'--attention focused by structure and formal arrangement on the complex and evolving emotional field--that IS the poem." (The Flexible Lyric, p. 83)
"Discursive logic is always linear. [...] Language can only be linear; therefore, it makes itself available to rules (syntax), to a lexicon (dictionaries supply fixed denotation--meaning that does not change in context), and to translation. [...] When we witness a painting, or a man biting a dog, the lements of the visual image impress themselves simultaneously; it is only the need to verbalize them that makes them linear." (The Flexible Lyric, pp. 84-85)
"To a large extent, even though as language objects poems must release themselves discursively, and even though some of them undertake the discursive tasks of narrative or argument, history or philosophy, the best poems of any mode become nondiscursive symbols. That is, syntax and diction work not only to convey discursive information, not only as 'rules' and denotative items from the lexicon, but also to duplicate, with their sounds, something of the inflection we respond to, in life, non-discursively. Isn't this what we're after?" (The Flexible Lyric, p. 85)
"Making character known also needs idiom, and prose more easily sustains the idiomatic (all those unstressed syllables in speech rhythms--by the pond, under the tree, after the dance); in poetry, whose first allegiance must be to music, nothing wears so quickly as the flat line." (The Flexible Lyric, p. 97)
"Sequence, subsequent, consequence--the root is 'to follow.' Narrative can depart from or rearrange chronology but always plays against the presumption of its stability. If lyric structure fixes points on a graph, narrative fills in the line between them, on which to hang discursive information." (The Flexible Lyric, p. 102)
"A plot line, then, of sounds, of feeling. In music, one speaks easily of 'line'; each note, even repetitions of the same note, must contribute to the phrase, which builds and subsides in volume or pitch or intensity, and each phrase must relate likewise to the others in the overall structure of the piece. [...] What carries these progressions, or phrases, into the reader's right brain, bypassing the discursive habit of language, is the texture of repeated sounds[.]" (The Flexible Lyric, pp. 108-09)
The Flexible Lyric, Ellen Bryant Voigt.
The Life of Poetry, Muriel Rukeyser.
The Sounds of Poetry, Robert Pinsky.
I will direct you to these resources: Lines and Linebreaks
Denise Levertov--"On the Function of the Line"
Good line breaks
Today's assignment: Count how many lines are in your poem. Consider what would happen if you drew some lines into others or, alternately, broke some lines into smaller ones. How would that affect the read--the notation--of the poem?