After the posts on logopoeia and phanopoeia, I guess I have to finish with the third way of “charging” words according to Pound:
Melopoeia, wherein the words are charged, over and above their plain meaning, with some musical property, which directs the bearing or trend of that meaning.
For Pound melopoeia is not the third but the first of the three ways because the special relation music and poetry have. Poems were intended to be actually sung, so it’s clear they had to conform to a specific rhythm, event if it was just to ease the task of memorizing them. This property has been a bit forgotten with the advent of free verse, though “no verse is free for the man who wants to do a good job” as T.S. Eliot said. I think here lies an important point. Free verse cannot be an excuse to hide the musical limitations of a poem, it should be used when the poem needs it, that is, when what the poet wants to say is better said with free verse, because the choice of a specific metric will tie his possibilities and damage the poem.