I can even bet that finding the rhythm in a poem it´s a process that lasts as long as someone is reading it. BUT, have you ever read a poem to someone else? Not yourself, you will never know if you´re a good chef if only you taste your food.
Give it a shot and I assure you that something so intangible as a poem can´t be separated or classified by procedures (free poetry is a clear example).
The rhythm ends with the last period of the poem (do not confuse it with prose), but the beauty of it echoes through eternity.
In analyzing a poem, finding the rhythm is usually the first step because it is one of the key to finding the hidden meaning of the poetry. And it can further analyze the symbolism behind it, like finding out the reference behind it or even searching on the stanzas more.
