"Swing" tends to be one of those terms treated in the dance industry like style or charisma -- We don't know exactly how to define it, but we know it when we see it.
But I get to differ.
We dancers are a touchy-feely bunch. It's what makes us great artists, but at the same time it tends to cost us in the teaching department. We tend to describe our impression of what is happening, rather than the physical reality. Our use of the word "swing" is the perfect example of this.
The action of swinging requires that an object (known as the "effort") be attached to a fulcrum, and move freely along the path of an arc centered around the fulcrum. Many things in dancing are typically described as "swinging", such as arms, legs, and even the body as a whole. But how often is it that we are truly seeing something swing?
Let's take the example of the whole body: The "swing" we speak of in the Waltz & Foxtrot is supposedly a whole body swing, but where's the fulcrum? The only thing out bodies are attached to is the floor. So it's safe to say that this is not in fact an actual swinging action at all; Rather, it's an action that *emulates* a swing, or gives us the impression of swinging in the way it looks and feels.
Don't get me wrong... I do think it's perfectly reasonable to use the term "swing" to describe that whole-body action in the teaching of ballroom dancing, but I also think we need to (1) define it as merely the emulation of the actual motion, and (2) set some criteria to help define what ballroom swing is. Here are mine (with regard to whole-body swing):
(1) The body must move along the path of an arc
(2) The angle of the body should incline toward the imaginary fulcrum
(3) It must accelerate and subsequently slow down
(4) The motion cannot be wholly controlled or bound throughout. It must release at some point and be allowed to move freely of its own momentum.
To my sensibilities, these 4 things are needed in order for a body to give the impression of swinging. If you eliminate any one of them, the resulting action would not be one that would make someone look at it and say, "Yeah, that's swinging".
Take the example of a child on a swing: Pull him back (and upward), then let him go, and he'll swing along that arc. But if you were to hold him the entire way, guiding him along that arc at a snail's pace, you can see how the arc is not the only relevant factor. Too much control cancels out the acceleration and free release of the motion (#'s 3 and 4), and he is no longer swinging.
Now where leg swing is concerned, the situation is different: Your free leg does indeed have a true fulcrum: The hip joint. (Theoretically you can also swing at the knee joint, but for now let's just take for granted that we don't). The actual fulcrum guarantees that we will meet criteria 1 and 2, assuming the path of the effort is an uninterrupted arc. Now if you assume the foot is the effort, you'll say the leg isn't swinging because it's moving along a straight path (the floor), which makes it an interrupted arc. The problem lies in your assumption: The foot is not the effort; The knee is. In other words, the swing is the action of the knee (effort) from the hip (fulcrum).
The knee and ankle joints of the free leg give you control to change the shape of the overall structure, essentially lengthening and shortening it, so that you can keep your foot on a straight path as the upper leg swings along its arc.
(continued next post)
