Does anyone have an easy way of explaining CBM ?.

In a word: Rotation.

CBM is a specific type of rotation, having the following qualities:
I hope this is clear enough. As with any principle of body mechanics, one can get overwhelmed with details. CBM is probably the single most misunderstood concept in ballroom dancing, but it shouldn't be. The basic premise itself is quite simple: It's a type of turning action.

Regards,
Jonathan

Jonathan.Thanks for the good advice. I think you would agree then that a good excercise, as I was recently told,would be to swing the opposite arm to the leg solo down the floor Foxtrot style all heel leads.And if we hold that line over two steps we have CBMP on the second. I'm just beginning to understand when I am told dancing is only an exaggerated walk. Thanks again.

Swinging the arms can give you some feel of when the rotation should happen, but be careful because simply rotating your top doesn't count as CBM. You have to get the hips turning too.

A simple way to avoid using your arms while practicing CBM is to place your fingertips on your sternum while keeping elbows extended outward as they would be in dance position. This confines the arms somewhat, making them less likely to reach forward and back into a distorted position that tricks you into thinking you've rotated when you haven't (or tricks you into thinking you've rotated more than you actually have). The fingertips on the sternum also heighten your awareness of your true orientation throughout the process.

Jonathan

Not quite.

First of all, CBM does not necessarily need to result in CBMP. If you dance a basic reverse turn (left box turn), you dance with CBM on step 1 but it does not result in CBMP.

Secondly, if you do end in CBMP, it would be on the very first step, not the following step. If you step forward on your left foot while turning the body to the left, if you turn fast enough, you will end with your right side in advance of the left. However, once you begin the following step on the right foot, you now have the same side and foot working together, which is the opposite of CBMP. It's known as "...side leading" (eg left side leading, right side leading).

To get CBMP on two consecutive steps, you need to turn both ways. For example, step LF while turning to the left, then step RF while turning to the R. This is fairly uncommon in ballroom dancing, since most of our actions are "swinging" actions, and you can't really swing if you keep switching directions.

You should understand that CBMP is a very specific position used in very specific circumstances, most notably in promenade and outside partner positions. It's not simply an automatic result of turning with CBM. In fact, CBMP only exists in a few rare exceptions in closed (in-line) position. So you would best be served by practicing CBM that does not end in CBMP.

A better exercise to understand CBM and CBMP is to dance sets of 3 consecutive steps. Only the first step is a heel. Prior to the first step, you wind-up your body in the opposite direction. For example, if your first step is forward on the right foot with the turn to the right, you would first wind up by turning the body to the left before you begin. As you take your first step forward, you start turning right so as to unwind. You want to turn so that when the step is complete, your body is squared off to the feet. If you overturn, you'll be in CBMP, which is wrong. As you continue to move forward towards the next step, you'll continue to turn, and now the left side will be in advance of the right. But that's not CBMP because now the same side and foot are leading (left foot, left side). After step 2 is placed, you stop turning but you continue moving forward into step 3, which is in CBMP.

Now you can repeat this process starting with the next foot. You'll notice that at the end of one sequence of 3 steps, you'll already be conventiently wound-up to begin the next sequence.

Notice also that the first step has CBM but does not end in CBMP, whereas the third step is in CBMP, but because you don't turn, there is no CBM. If you understand this, you've got a handle on the concepts of CBM and CBMP.

Regards,
Jonathan

Perhaps what Nod meant was that if you use CBM, and then hold that position for two more steps you will be in CBMP. For example, a feather - CBM on 1, resulting in side lead on 2, CBMP on 3.

Except in tango, we never achieve CBMP by rotation occuring during the CBMP step - it is always a result of a rotation taken on an earlier step which has set up a trend of moving across the body.

Of further interest in the feather is that in the basic version there is offically no turn on any step. While the technique book has "CBM" as langauge for specifying rotation of the opposite side towards the moving foot on step one without producing a turn , it does not have any means of specifying if such a rotation should continue on step two. I believe that the apparent lack of need for such language suggests that the rotation is actually to be completed during step one, and not continued into step two - if it were supposed to, there would be a way to say that. This would mean that step one actually is in the same "CBMP" position as step three, but there is no need to repeate that with a CBMP annotation since the fact that you are rotating already says so.

Jonathan will probably however disagree. He tends to point out how we have steps with CBM only, with CBMP only, and with both - however outside of tango, CBMP is purely a function of what you did previously, while CBM is purely an indication of what you are doing now. It's quite possible to have neither, either, or both without requiring that the result of stepping with CBM actually be any different than stepping into CBMP.

Or to put it another way, there is an almost completely unfounded fear of producing unwarranted CBMP.

It's unfounded because you can't produce CBMP via rotation - if you rotated to end up in a position, you used CBM, and assuming CBM is called for, that is good.

The only way to produce erroneous CBMP is to forcibly alter the track of your movement as you take step 1, in order to move in a diagonal direction across your body when your momentum had not been sending you that way. This is a completely different problem - basically it would be if you were set up for an inside partner step and decided at the last minute you'd rather go outside - a stunt likely to be punished with a kneecapping.

(The fact that lack of carried through momentum allows us to alter our track on a whim in tango is what makes the CBM/CBMP relationship in that dance different)

Anonymous. That's exactly what I meant.Holding the same line over two steps as in a Feather Step must produce CBMP on the second. I was also recently told to watch how this is done because the shoulders have a bigger range of motion than the hips and they are much easier to move. So in other words don't try to match the hips with the shoulders. They hips should move but don't over do it. Any thoughts on this one.

Yes, the shoulders can rotate more freely than the hips.

But we also have to ask, what does rotating the shoulders accomplish?

In a feather type outside partner step, the maximum clearance for the moving leg would be achieved if the shoulders - and hence the offset in the hold - where kept perpendicular to the direction of travel and only the hips were rotated. In contrast, most want to feather the shoulders towards the direction of travel.

This seems to be an area of technique open to further investigation.