What song/mix in the Pisa scene?

At just about 1hr:21minutes into the documentary, Keith is at a public event (in Pisa?) and is shown briefly DJ-ing for a small outdoor crowd. He slides a fader up on a mixing board and a dance club mix comes on with the lyrics "Won't be no hard times, no suffering. Someday we'll all be free". Any idea what song/mix this is? It sounds so familiar, it's driving me nuts. It's only on for maybe 15 seconds before fading out to ambient sounds while he paints a wall.