The following is taken from an answer I gave to questions I received on a great writer’s forum I’m a part of. I’ve cleaned it up a bit for readability, but this is essentially the text as posted. As such, it is not even close to a complete handling of the topic. However, it was well received and people thought it was useful. I hope you do as well.

Could you outline the importance of form and meter?
Does having a meter improve the poem?

Let me answer your questions in reverse order.

Does having a meter improve the poem?

It depends on the poem. If your goal is a metrical poem then of course. If free verse, no, but in both case it is critical that you remain conscious of the syllabic arrangement of the words you are using and the impact on not only the music, but the meaning, and the emotional effect of your poem.

The effect of a series of unaccented followed by accented syllables is the same regardless of form. The same with successive accented ones. The former has a lazy almost conversational tone and the later communicates urgency, sometimes frivolity. This is true no matter of form. That’s only two examples, but I hope you see where this is going.

In traditional metrical verse there are standards governing the effective use of these sound patterns. These patterns evolved as poets explored the most effective means of conveying their intention in a pleasing manner. As rigid as these forms can seem, they are not arbitrary, and the best practitioners often deviate from their chosen pattern at key points for effect. Think of accidentals in music.

Could you outline the importance of form and meter?

No. Not without writing a book. I will try and illustrate. First with a metrical poem:

No Bird – Theodore Roethke

Now here is peace for one who knew
The secret heart of sound.
The ear so delicate and true
Is pressed to noiseless ground.

Slow swings the breeze above her head,
The grasses whitely stir;
But in this forest of the dead
No bird awakens her.

Can you hear how the music has a delicacy that fits perfectly with the imagery and the theme of poem?  Its opens in iambic tetrameter,  followed by a trimeter. The pattern then repeats. It culminates in a sense of extreme gravity by the time we get to the last line where “No Bird” can almost be read as a spondee and then the 3 syllables of “awakens” rush to the finality of “her”.  Which is fitting since the poem is about just that, the finality of her, the subject of the poem. This is a very cursory look at a great poem that deserves much better treatment, but I hope it helps.

Now for something completely different:

This is Just to Say – William Carlos Williams

I have eaten
the plums
that were in
the icebox

and which
you were probably
saving
for breakfast

Forgive me
they were delicious
so sweet
and so cold

This poem has been analyzed in several ways. Some that make it out to be an obscure reference to man’s fall, or some form of comment on repression – the whole forbidden fruit thing. I take it on face value. It’s delightful. Not everything needs to be deep. In any case, its structure an tone are whimsical.

This is no accident. Dr. Williams’ use of line breaks and accents are brilliant. If you just beat the syllables out on a table they are a joy. Combine the sound and the form and it’s easy to picture a man playfully teasing his wife about eating her plums. So again the words and the structure combine perfectly to convey the authors intent.

So at long last my point: Both of these poem are excellent examples of completely different styles. If you really want to understand the importance of the forms involved, try to apply their respective styles one to the other:

Here peace is
For one
that loved
some music

or

As for the plums that were for you
I ate them and was feed
you planned to eat them very true
Once risen from your bed.

It really is about picking the style that best fits your voice or your intent at the time. Please forgive any technical inaccuracies, etc. I think the point should still be clear.

Some reading if you’re interested:

A Poetry Handbook – Mary Oliver
Rules for the Dance – Mary Oliver
Free Verse: An Essay on Prosody – Charles O. Hartman
Poetic Meter and Poetic Form – Paul Fussel