Taking on
davem's road comparison...each being bound by the Music has the freedom to choose a fork in the road, but Men are free to build their own roads. But in the end, they will realize that Eru has designed the whole terrain in a manner that they could never have comprehended; whichever paths they chose, they ended up right where Eru wants them to.
Or with
Formendacil's play metaphor...the Music-bound people act as the Music sways them, Men do improvizations and affect the whole plot, as well as the former's acting. But once the curtain falls and they all step back to watch how the play went, they will see that Eru has created such a versatile script that though the characters deviate, the ending will be as Eru originally wrote it.
In some cases a road-builder might fall off a cliff or an actor off the stage, but these instances are consequences of their own choices (or temporary blindness
). Eru never meant anyone to be hurt. But being a perfect gentleman, he lets them go or act the way they choose, yet allows them to find out what is beyond the paths they forged, or what their action's repercussions on the story or on their fellow actors are.
Now this brings me to think, is the Men's freedom from the Music a reason for their greater divisiveness and, very loosely, their gullibility as opposed to the Elves? Is this why they are much easier to sway to the side of evil or why they seem to have more 'branches'? Because they have more roads to 'choose from' or more roles to 'assume'?