The Oxford Dictionary tells us that poetry is ‘composition in verse or metrical language.’
I would add that it does not have to rhyme, although in its purest form it does, but it does need to conform to a recognisable metrical form that distinguishes it from prose.
In my opinion poetry should be like music, written in words instead of notes, of which the best example I know is the opening lines of the Choric Song from Tennyson’s “The Lotus Eaters:”
There is sweet music here, that softer falls
Than petals from blown roses on the grass,
Or night-dews on still waters, between walls
Of shadowy granite, in a gleaming pass;
Music that gentlier on the spirit lies,
Than tir’d eyelids upon tir’d eyes;
Music that brings sweet sleep down from the blissful skies.Tennyson - 'The Lotus Eaters'
Modern so-called poetry, at its best, may be musical, but it is really only prose written in irregular lines.
During the course of a correspondence with Polly Clark, then the Resident Poet of the Southern Daily Echo, (she had kindly referred to me in one of her articles as ‘a distinguished rhyming poet’), I praised her for one of her poems “My Life as a Hack,” that I had genuinely admired, (it had included a phrase ‘scurrying on QWERTY legs’ which I would dearly love to have thought of myself), but I suggested to her that if I had written it out in continual lines and had shown it to a group of teachers or grammarians, they would have said it was prose; and I asked her how it could become poetry simply by being written in irregular lines?
In her reply she confessed that the poem had not been printed as she had written it, but it had been altered in order to fit it into the column, which raises an interesting question.
The work itself remained Polly’s of course, but if its arrangement into irregular lines turned it into poetry who, in this case, was the poet? Polly or the compositor?
My other complaint in regard to modern poetry is that so much of it is incomprehensible to all but a few, and even that small degree of comprehension is dubious. It seems to me to be completely pointless, and a waste of time, to write something that no one else can understand.
A poet is only completely successful if he has awakened in the mind of the reader an echo of his or her own emotional experiences, who may not themselves have been able to put their feelings into words.
I believe that modern poetry shares with modern art the operation of the ‘Emperor’s clothes syndrome,’ whereby many of its adherents do not really understand it but are unwilling to admit their ignorance in case they are thought to be stupid or uninformed.