folkstuff

—— folk family and jam

thousandmiles

Fare thee well I must be gone
And leave you for a while
Where e'er I go I will return
Though I go, though I go ten thousand miles
Though I go, Though I go, Though I go ten thousand miles.

Ten thousand miles it is so far
Toleave me here alone
Where I mat lie, lament and cry
And you, you'll not hear my moans

The crow that is so black my love
Will change its colour white
Before I prove false to you my love
The day will turn to night

The rivers never will run dry
Nor the rocks melt with the sun
I'll never prove false to you my love
Till all these things be done
 

From   Steve, Joan Baez perhaps

About
It has a fairly characteristic jump in the last line.  To some note only just within your range (and that's if you're lucky).  It being within your range doesn't mean that you'll necessarily hit it. 
My range hasn't increased (though my ability to hit notes believe it or not has), so the song falls into two parts - the first part where it goes down towards the subsonic, and then the last bit where it beckons enticingly from the limits of my ability.
So it is challenging.  To sing as well as to hear.  Perhaps that's part of the attraction.

There are millions of these songs - the faithful lover and all the things he will do.  (And continued into pop - just think of Motown's ain't no mountain high enough etc.)
Just as there are millions of songs warning girls not to believe a word of it.