The enclosures denied people access to land. Songs about the enclosures might be appropriate - but don't seem to exist, I'm afraid. There are plenty about poachers - and transportation - though.

The Albion Country Band - Gallant Poacher

Now come all you lads of high renown
That like to drink strong ale that's brown
And pull a lofty pheasant down
With powder, shot and gun.
He's a gallant youth, I will tell the truth,
Oh he's crossed all life's temptations ways,
No mortal man his life could save
Now he's sleeping in his grave,
His deeds on earth be done.

John Clare wrote about the enclosures; The Mores

Each little tyrant with his little sign
Shows where man claims earth glows no more divine
But paths to freedom and to childhood dear
A board sticks up to notice 'no road here'

And on the tree with ivy overhung
The hated sign by vulgar taste is hung
As tho' the very birds should learn to know
When they go there they must no further go

Pete Morton wrote The Shepherd's Song about John Clare - it's wonderful!
http://www.youtube.com/watch?v=z0QOkOj2AQg