Come to Dance the Macabray (with Book Carts)

I first heard about ALA's Book Cart Drill Team competition after Jon Scieszka and Mo Willems stumbled upon it a few years back and took over the commentary.  This year I finally managed to drop by just it time to see this group.   (I left after this, but heard from Mo that there was one more group that did some sort of John Cage sort of thing.  Anyone see it and can tell us more?)