Hi Terrence am not arguing about the arm or frame position. For me it seems to be a matter of what dance/lead principle you apply. The principle I was taught was that unless you lead the lady she will continue in the direction she is going. So if she steps back on her right foot for 1 and I don't apply the break then on 2 she should also step back. So in on1 salsa (or Cuban) I need to first apply a rubber band effect on 1 and then on 3 to lead her out to CBL. The way it sounds to me for ET2 is that you only need to apply lead on 7, perhaps because of the basic action and the principle that the lady keeps going back and forth in a line when the door is openned. But I might be wrong for ET2 so am trying to understand because I don't dance it.
And if we say that break points don't matter then this leads to the other discussion on breaks and why they seem different between on1/Cuban and ET2.
I go by the same law.
I never assume that the lady assumes anything.
I perceive the kinematics of the dance in a way that somewhat reflects the first and the second newton's laws of motion.
Part one: Contra. (Net force = 0)
When the girl and I maintain our frames and give each other "Contra" - then net force is zero.
From my (or hers) perspective, we "don't move at all". (Even if a 'watcher' from outside sees us doing a back-and-forth basic step, to my, or her eyes, by maintaing the contra, we "do not move"). This is similar to a person sitting in a bus. To the "outside world", ofc, the bus (and the person inside it) move, but from the person's perspective (Compared to the bus), he just "sits in place".
When the follow and I strive to keep the contra, we can "stick".
Anyways, According to the first law of Newton, in that scenario, we will either stay at rest, or keep our previous velocity.
This goes well with what you said: If the girl was led to move, she will continue her motion, unless the lead excelates her:
Part two: We cheat the Contra by moving.
Let's assume I apply a force of "2N on the girl, and she does 2N in return. (That's our "Contra") According to what I said earlier, we shouldn't move. (Or keep moving in the sace velocity we had before).
Now I Increase the force to 3N! (Either by Pushing with the hands, which is considered bad, or by, amm...pushing the floor to go forward!)
two things can happen:
1) Girl wil "fight it" and push me back in a force of 3N (Instead of the previous 2), but that's just...resisting your lead.
2) Girl will
*Move*. What determines how much she will move? A length respective to difference between you and her's "push". (In that scenario we applied 2N on each other, and I increased the force I aplly to 3N, so the difference is 1N. If I increased it to 4N, the difference would be 2N, and so she would move twice as far. We can also see that if our innitial contra was 10N vs 10N and I increased my force on her to 11N, this is just as the same as a contra of 2N and 2N, and me increasing my force on her to 3N. Differnce is still 1N!)
Now, the difference of force should make the girl excelate, and so move faster than me, and that would create distance between us.
But according to part one, I strive to keep our contra, so I will "Cheat" it, and move with her - "sticking" to her and perserving the "Net force = 0" feel.
Part three: We cheat a world "with low friction".
Imagine pushing a sumpermarket cart...on a hard asphalt. Eventually it will stop due to friction.
Now imagine pushing the same cart, this time on ice. It will really tend to "remember" the motion he was led to do, and maintain it.
By moving on her own, the girl fakes a world with "low friction" - she can cotinously maintain her motion without slowing due to friction.
When I lead, it's like moving a supermaket cart. IF the girl does the first two parts well, and she's light, this would also feel like moving with a supermarket cart...on ice.
Now, when you do your shopping - do you have have to apply an LA-like Rubber band effect, to stop its movement and then start going in reverse?
Do you usually do breaking steps when you rotate with your cart?
I bet you stick to it, keep your arms at the same length during most of shopping, "push it" by...just pusing the floor and progressive to a direction you desire...and when you want to turn, you just do it gradually -
abusing the motion that the cart already has to make it nice and smooth,
-Yes, of course there is *some* pulling and pushing done to maintain the contra, and you *do* apply lead...but so long as you and your partner stick to those "three parts", it can be done in a relatively smooth way - no sharp LA-ish whips, catapults or obvious breaks are needed. You don't do it with a supermarket cart - and you don't really have to do it with a girl who wishes to follow you and maintains her contra.
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The way I see it, your "common-center' in NY Style is usually quite light, relaxed and constant.
In LA and it changes a lot throughout the dance, as instead of being relaxed and constant, there are huge increasements and deceasements in force, and muscles are being stretched and compressed much more. (I also noticed that LA dancers do it in a sharp, "stacatoish" way, while WCS dancers know how to apply those dyanmics in a more gradual, "higher-resolution", "Legatoish" and smooth way).