"The Origins of Free Verse" by H.T. Kirby-Smith (Univ of Michigan Press, 1999)

Readable and opinionated, tracing free verse through the usual suspects - Milton, Cowley's Pindariques, Ossian, Whitman, Arnold, Laforgue - to Eliot, who the author likes. He sees free verse as a reaction - "Varieties of free verse in English poetry have appeared and reappeared in a series of cycles that began in the late sixteenth century and continue at the end of the twentieth" (p.17) and regrets the over-reactions - "Too much free verse of our own time is an effort to renounce this rhythmic and linguistic inheritance ... and an attempt to replace a shareable metric with an indefinable authenticity of personal utterance" (p.274). He thinks that the best free verse poets know their metrics, and that "free" only makes sense in conscious relation to the constraints. He weighs in against the concept of organic form, which misguided though it is, "thrives on the most fundamental ideas and convictions that most human beings live by - the concept of the immortality of the human soul, for example" (p.28).

But I don't think free verse needs to gain dynamism by comparison with fixed forms, though people who grew up with fixed forms might feel that way. I don't think the word "free" should be taken too seriously - "free", "looser" and "rules" are loaded words. Maybe it's true that "[Milton's] writing of free verse, if we can allow that term, is quite in keeping with his advocacy of divorce, his defense of free speech, his belief in free will, and his general cantankerousness" (p.74) but I don't think the same correspondence applies today in the US.

This attachment to metrics continues into his discussion of the prose poem - "the prose poem requires ... not only the talent but the works and reputation of an accomplished metricist to make it successful" (p.258) - which is like free verse only more so: "If lack of ability safely disguises itself for a time in bad free verse, the ultimate refuge of bankrupt talent is the prose poem" (p.255). If you know any prose poem writers, I suggest you lock up your daughters. He points out that "Numerous poets have had a fling at the prose poem at one time or another, but the results ... seldom find a place in anthologies and ... Books written on the prose poem differ radically in their emphases ... Personal preferences ... play as large a part in the evaluation of the prose poem as in its composition" (p.264), and hence "It is unlikely that a well-established canon of prose poetry will ever be established [because] ... the common reader has not yet found it to be a memorable genre" (p.264), which seems fair enough.