Another episode that shares features with the Pied Piper events took place in 1237 in the town of Erfurt, 271km south-east of Hamelin. A group of children marched in a dancing procession towards Arnstadt, 15km to the south, where they were said to have collapsed with exhaustion. Unlike the children of Hamelin, the Erfurt youngsters were rescued by their parents, who took them back to their homes. Still, some of them were said either to have died or remained afflicted with a permanent tremor.
The events at Erfurt are considered to be one of the first manifestations of the mediæval phenomenon known as the Dancing Mania (see FT:203:30–34), usually interpreted as a form of mass hysteria related to religious fervour. Dancing Mania was reportedly spread by “the sight of sufferers, like a demoniacal epidemic, over the whole of Germany and the neighbouring countries to the northwest”.  Those affected were described as unable to control their movements, or to stop their endless dance, and many were said to have died of exhaustion. As with Hamelin, we have an image of a crowd of children led away by music, perhaps to their deaths.
An article at Fortean Times lays out several possibilities for the disappearance of 130 children from Hamelin. Link