Definition

Poetry is a condensed essay written in a way that is melodious to read and where the wordings are stunning and appealing and used in a new combinations which can give them a new meaning for the reader.
Poetry is written in meter and verse
The words are arranged on the paper in a graphically attractive way.
It is mysterious and compressed. Hard to retell and there is no story
It is a model or theory of a problem
Poetry is prose with lines according to your own discretion.

Ambiguity
Abstraction
Generalization
New combination of words and word elements
Juxtaposition
Repetition with variation
Mystery, masks, pictures, metaphors, analogies
Word music
Condensed, compressed
Hard to retell
No story
To create by words

Some kind of a riddle as opposed to song writing
Songwriting should be simple and clear, with rhythm and rhymes

Analyze As writer’s poem
As reader’s poem


Meter

cesur /

trochee + -
iamb - +
anapest - - +
dactyl + - -
raising peon - - - +
falling peon + - - -
spondee + +
pyrric - -
choriamb + - - +
amfibrack - + -

A trochee is a iamb
a iamb is a trochee
an anapest is an anapest
Da´ctylos is Greek for dactyl

Metrical lines in poetry:
MONOMETER one foot
DIMETER two feet
TRIMETER three feet
TETRAMETER four feet
PENTAMETER five feet
HEXAMETER six feet
HEPTAMETER seven feet
OCTAMETER eight feet

Just because a poem is written in iambic pentameter lines doesn't mean that every single foot is an iamb. In fact, the most interesting poems substitute feet.
Beat or cadence or tempo or foot.

H2s

Repitition
Repetion is an efficient tool to get a message across. Like nursery rhymes and beddiebys, most modern hits have few words - easy to learn and easy to remember. Like beddiebys, hits are for listeners and they should be easy and able to be learnt by heart and remembered
Basically same with poetry, which could be defined as words arranged according to some kind of melody or tune - rhythm that is repeated - and created, written and printed for listeners; for readers only to be learnt by heart. Stanza basically means something that could last.
In demagogic, like in promotion, you use repetition to get a message across. You can repeat in the same speech, same paragraph or over time.
Repetition also gives a dramatic effect to a poem. For the dramatic effect it is enough with a few repeated - parallel - words like in

Thank you Lord for roads well paved
Thank you Lord for bumps ahead

Rap music is another kind of repetition. A monotonous repetition of rhythm.

Contrast

Opposite to the concept of repetition is the concept of contrast. Two elements should contrast each other in order to give an effect. In art design a big and a small element should contrast each other, a horizontal line should contrast a vertical in order to get some kind of a tension to the picture.
Also in fashion there is a concept of contrast. A new fashion following an old one has to be almost totally different from the old fashion. Long skirts have to follow short and vice versa. The new fashion cannot be just a little longer or a little shorter.
In poetry a new line should follow that is totally unexpected and not foreseen or anticipated. Like a number of joke punch lines or one-liners.

Free verse

"No verse is free for a man who wants to do a good work. There is no freedom in art"
...
"Only a bad poet could welcome free verse as a liberation from form"
T S Eliot

New

New combination of words
Harmony
Value to the writer and to the reader
Rhyme
Rhythm
Simplicity
Openings
Turning points
Masks, Metaphors, Allegories, Symbols (ambiguity)

Give the reader something he did not think he could enjoy and need

Unexpected
Diguise, kenninger (Islandic poetry)

Contrast, tension
Reduction
Simplicity
Repetition
Harmony
Balance
New, unexpected

Compression

Reduction of elements. A reduction of the number of elements results in a more powerful art design. Or the principle of "dilution of arguments" in demagogic. The more arguments used to support an idea, the less convincing.
You may claim that compression is the essence of poetry, that compression can turn prose into poetry. Compression is the way we let words achieve their true power, the way we let them show us what they can do. In German the word for a poem is “dicht” meaning condensed.
Redundancy makes us sloppy thinkers and writers. Once we let words overlap -- not forcing them to pull their own weight -- we start to forget what each word really means. We start to say, oh, you know what I mean -- without any longer knowing what we ourselves mean.

Repetition

On the other hand, there are those who say that redundancy and repetition are the only things that turns words into poetry. With no repetition, we get no poetic sound effects, with no repetition, we get no poetic rhythm, with no repetition, we get no poetic form, with no repetition, we get no emotion.

Ambiguity

Ambiguity can be seen as a combination of compression and repetition - sometimes combined in one word! That something, of course, is ambiguity.
Just to clarify, ambiguity doesn't mean vagueness. Ambiguity has definiteness in its lack of a single, simple meaning. A word or phrase or poem is ambiguous when it has more than one meaning.
Lots of words have very different meanings buried within, like "cleave" (cut apart or stick close), "primate" (a religious official or a less than human animal), "compromise" (a reasonable trade-off or a betrayal), "sex" (gender or a potentially procreative act).
The problem with ambiguity is, that it makes things ambiguous. We can't tell what's going on? Is a lyric that seems to be about the mysterious givenness of two genders just slyly trying to insinuate that everybody should copulate with everybody else like, well, like monkeys? Can't people just say what they mean? Shouldn't poets -- of all people -- know what they want to say? Isn't an ambiguous poet betraying the trust of his or her readers? Don't readers have the right to expect a kind of "straightforward talk from the heart" out of poets?
On the other hand, one might think that the joy of ambiguity is in its capturing the authentic complexity of lived life (how about that partial repetition?). We do feel two (and more) ways about things - our friends, mates, jobs, countries. And it's not just that people, ideas, and things inspire multiple reactions in us. Those same people, places, books, animals, and stars are themselves complex existences. How can we capture them in poetry if we use one-dimensional language? Don't we need ambiguity in poems to convey the process of discovering that someone has depths that can be very different from his or her surface?