…the best poets who fought for the legitimacy of free verse in the early years of the twentieth century were not trying to make us choose between apparently different kinds of poetry; they were attempting to open our ears to a wider range of poetic possibilities. Following them, a poet like Justice learned as much from Williams and Pound as he did from Shakespeare and Keats, and one of the most important lessons was that the language of a particular poem may or may not demand the whole tool kit. If rhyme is jettisoned from a poem, what tactic must flex its muscles in order to keep the poetic contraption in the air? Meter. And if meter is foresworn? Line. And if line is abandoned? Syntax. And if syntax is abandoned? Diction. Sometimes it will be necessary for a poet to remember every tool in the kit; at other times it will be equally crucial to forget them, though nothing can be forgotten if it has not first been remembered.

– James Longenbach, “Line and Syntax,” The Art Of The Poetic Line, 24