"The Army has cleared plans for an atheist-themed concert at Fort Bragg..."

"... organized in response to an evangelical Christian concert there last fall."

What songs do you play at such a concert?

Prominent atheist Richard Dawkins is scheduled to appear at the event, along with musicians, speakers and other entertainment....

Oh, don't you love his songs?

Okay, so I Googled "Top 10 Atheist Songs" — and some are really more properly characterized as anti-religion songs. #1 is what you'd come up with if you thought about it a bit...

Imagine there’s no countries
It isn’t hard to do
Nothing to kill or die for
And no religion too...

Here's a discussion of atheist songs. Somebody suggests The Internationale:

No saviour from on high delivers,
No faith have we in prince or peer.
Our own right hand the chains must shiver,
Chains of hatred, greed and fear.

I think a more inventive approach could be taken to finding the truly atheistic songs. Songs about the supremacy of the individual acting alone express a belief in the absence of God. For example, "The Greatest Love of All" (the greatest love is self-love). And I've long thought of this song as fundamentally atheistic.