What is the dominant rhythm of the poem "All the World's A Stage" by William Shakespeare?

It's interesting how this speech from the play As You Like It has captured people's imaginations so much that it sort of detached itself from the play and became a poem in its own right. We know that this poem is about how everybody just moves through life, playing parts, doing the same things people have always done; at the same time, we all go through identical stages of life, from a helpless infancy to a helpless old age. Understanding the rhythm of this poem can help us appreciate its message even more, so let's take a close look at it.

Here are the first few lines, which will work as a representation of the entire poem, since it's highly consistent in its rhythm:

"All the world's a stage,

And all the men and women merely players;

They have their exits and their entrances,

And one man in his time plays many parts,"

As you can tell when you read this aloud, the rhythm is very steady and regular. It almost feels sing-songy, or droning, like the speaker has a lot to say and isn't going to quit until he says it all. This droning, even rhythm is dominant throughout the poem, with only small variations in some lines.

Like with much of his work, Shakespeare composed this play in iambic pentameter, meaning that most lines have ten syllables, and those syllables are spread out across five iambs, or units of sound that include a first unstressed syllable followed by a second stressed syllable. 

Let's see how that works in the line "And one man in his time plays many parts." Count up the syllables and you'll see there are ten. (1: And. 2: one. 3: man. 4: in. 5: his. 6: time. 7: plays. 8 and 9: many. 10: parts.) And listen to the pattern of unstressed and stressed syllables, and you'll see how they're arranged in five units. I'll put the stressed syllables in capital letters:

 "And ONE

 man IN

 his TIME

 plays MAN-

 y PARTS".

The effect of the rhythm, then, is that each line sounds like "duh DUH duh DUH duh DUH duh DUH duh DUH," and the whole rhythm stays like that throughout the whole driving, unrelenting speech that constitutes the poem, with just a few little deviations from that pattern.

Noticing how consistent, even, and yes, dry the rhythm is helps us understand even more the plodding, jaded message of the poem: again, that life is like reliving the same play again and again, and that every stage of life is just another predictable act within the play.