This is the term they use in prison when someone gets hanged.
There were many hangings in Berlin, in which the victims would twitch and
jump at the end of a rope...hence, doing the "Spandau Ballet." Also, there were frequent suicides of Nazis being held for trial at the Spandau prison. A hanged person tends to jerk around and "
dance" if the death is caused by strangulation (and not a snap) they say. As the years went by it progressed to floorless
dance or waltz or the air rumba.