Body swing seems to be one of the most sought-after, but hardest to describe concepts in ballroom dancing. Personally, I've come to feel that swing is an essential game plan for how to execute a figure, a trend which ties together the steps, suggests where each will land, and makes them easier and more consistent with each other. Recently I got into a bit of an argument in another thread over the relationship between swing and foot closure. My personal belief is that foot closure is not really a distinct purposefull action, but rather a result of aiming the swing out of step one for the right point in space, and sustaining it through the rise onto step 2. I find that if I mis-aim the swing, it's fairly difficult to close my feet, while if I correctly aim and sustain the swing it would take purposeful effort not to close them. Similarly, if I want to do an open or foot-passing turn, I aim the swing lower and further (and feel it starting later) so that it will carry our bodies past the 2nd foot placement on to a third. And if I want to create a heel turn, I aim the swing shorter so that my partner will arrive on a straightening leg while her free leg swings under, but not past her body. But where does swing really come from? I'm not sure of the absolute origin, but one of my coaches stresses the timing of the foot action on step one as a major early contributor. Specifically, if the footwork says heel-toe, what that means is that your weight needs to be in the toe, with the heel starting to rise, by the time your free leg passes the standing one on it's way into step two. It took me several months to be able to sometimes create this, but in combination with sending the standing knee forward this helps get the lower body center really swinging forward and up. This actually has a lot of implication for how to take step two. Many of us initially developed a habit of reaching for step two by sending the leg forward from the hip socket. But if the entire body is swinging, the free leg can unfold and simply swing towards a line drawn through the shoulder and hip. With body swing designating the point where the free toe should land on step two, there is no need for the free leg to ever cross this line and reach forward of the body. Done right, the result is visually captivating - the free side of the body swings forward with a gentle curve, leg gracefully uncurling to create a long line in the instant that the toe finds its place on the floor. Several things can go wrong though. In a quest for extra time to get the lower body accelerating out of step one, it's possible to kill the energy and then try to recreate it from the foot action, rather than using a well timed foot action to add to and redirect energy carried out of the previous step 3. A related mistake would be to send the upper body backwards while the lower goes forward - swing is about the lower body passing the upper, by moving even faster than an upper body which is also moving forward. The person ahead of the swing also has an opportunity to kill it by prematurely moving away from their partner on a level path, before the start of an upswing can be felt and matched. Ironically such early movement actually becomes small movement, because without swing to incline the body line across the floor, the target point of the step feels under the present body position, rather than in line with the body projection.