"The shadows come to dance, my lord, dance my lord, dance my lord," he sang, hopping from one foot to the other and back again. "The shadows come to stay, my lord, stay my lord, stay my lord."
Prophecy, or mad ramblings? It certainly seems like Patchface knows something about Melisandre and her shadowbinding abilities. Pieces of above are repeated several times (p. 6, 17). Shireen states that the ditty frightens her.