In the folk context, a ballad is a song that primarily tells a story, rather than doing one of the many other things songs do.

So long as there are new stories to tell, there'll be a place for new ballads. To match up to the old ballads they have to be pretty good -but there's no reason we should expect them necessarily to follow the same storytelling conventions - though they are pretty good conventions which translate into modern life pretty well.

Here's a song by the Mudcat's InOBU (Larry Otway of New York), "Centuries of Pain, the Ballad of Amadou Dialo", which I think is one of the best modern ballads I've ever come across. (This set of words is the one I use, and it has a few variants from Larry's original, which is on the Cat somewhere. That's what happens with folk ballads):

Amadou was born, where humanity was born,
In a land forced to give away its best.
Where the stranger's hand, tore the wealth from out the land
even tearing her children from her breast.
Verdant forests cut down, and the gold ripped from the ground
her diamonds shine in many the foreign crown;
Ancient wisdom despised, history buried beneath lies,
her's a legacy of centuries of pain.

Well, he came to a land of gold, where his people's wealth was sold,
hoping here to find a place and make his way.
By the sweat of his brow, he would make a life somehow,
in this strange land far from family and friends.
In the streets of New York, he set out to find his dream
though the truth it was far from his hopes
still he thought he might get by, though he sometimes wondered why
all around him was a legacy of pain.

Coming home one night, in his hallways stark white light,
gunmen challenged him - he turned to ask them why.
As the guns together blazed, all alone stood amazed
Why was he being murdered by these men?
As he lay there on the ground, those strangers crowded round
tried to say that he'd been reaching for a gun.
But the truth was plainly clear, like so many more each year,
he'd been murdered by that legacy of pain.

A mother came to take, her child back to lie
in the soil from which humanity had sprung
And in that mother's tears, we saw the burden of the years,
of a land forced to give away her young.
Amadou, oh my son, what have these strangers done?
They never see the son I held so dear?.
Were they blinded by their badge, or by the color of your skin?
or by the legacy of centuries of pain?
Were they blinded by their badge, or by the color of your skin?
or by the legacy of centuries of pain?