Just a simple suggestion Rick, and forgive me, if it ain't your style.

Perhaps to get their attention, (and kinda describing the group you have to play for) perhaps a delta blues song, maybe Leadbelly or something of the like to describe the early trials and tribulations of slaves in the south.
Some kids might get into a decent blues riff, especially if you can correllate it into the overall theme of song to describe hardship and protest.

Like I said, it might not be really your style. But that be my two cents.

Steve