What is Swing. The dictionary says . To move freely back and forth or side to side while, or if as suspended. I have been one of those who was taught in the Waltz to move to the side on step two, body and all. Then I was informed that that's ok for a low grade medal. But to think of a Grandfather Clock with a pendulum. If the pendulum swings to the side and the above ( called the fulcrum point) moves at the same time and the same speed the pendulum can't swing, neither can we. Sway. Because the weight is over the standing foot, which includes the head and we are swinging, the fulcrum point wll be passed over to the new standing foot,( we don't want to swing in reverse), so we move over where swing will join sway. The other way I was as flat as a tack, rise to a mimimum with a very forced Sway.