Hmm. Chiming in by request.
Not certain where the confusion is here. Let's look at a few basics.
We understand that there are 3 body lines of vertical balance: right side (a line drawn from the inside of the shoulder[approx. where the bra strap/T-strap would be] ), center (from the base of the neck, through the sternum, through the navel, etc), and left side (same as right). In respect to these, we also understand that the head is placed atop the spine*, in a neutral position, if you will.
The first issue that I usually encounter is that dancers forget about horizontal balance. Those who do, often try to compensate by stretching the core, shoulders, topline, and spine in order to achieve an uprighted, corrected posture. More correctly, after setting the vertical balance, we rotate to the left to fnid horizontal balance, and accomodate the dance position. Incidentally, isn't it intersting that, at this point, the positions of the man and woman are identical... just flipped? As we rotate, here's where the differences come into being. As we rotate leftward, the 'right' side of the man is stretched upward, and the head is "found", not placed, over the left body line. The right side of the lady is stretched upward, and the head is "found", not placed, over the left body line. However, because of the dance position's open/closed sides, the man's spine is up and leftward; the lady's spine is up and outward.
OK. All of this prep is a necessary understanding in order to respond to what I believe the confusion is here. A major issue w/ both men and ladies is flipping the head all over the place. Balance, seeing where we are going, topline, school figure, and the devil made me do it
are the usual reasons that we hear. In actuality, one should only manipulate the head when going to promenade, and even then, there can be exceptions (like in waltz). For the man, the head remains centered... period. The d'oh! is, "Where is center?" This exercise will get one started well.
1. Stand afront of a mirror (simulated topline w/ arms)
2. Staring directly into your eyes, rotate the upper body slowly to the left (note how the dance posture is acquired)
3. Return to center
4. Staring directly into your eyes, rotate the upper body slowly to the right (note how a promenade posture is acquired)
Of course , this is just an beginners' exercise to see how it is not necessarily the turning of the head that creates desired position/s, but more than we realize, it is the rotation of the body. Thus, physically moving the head is unnecessary. When it is necessary, often we overdo it. Going back to vertical bodylines, we come to realize that the head only moves approx. 4"-6" at a time (from left center to center/reverse, and/or right center to center/reverse).
Hope this doesn't appear too soapboxy,
and hope it helps.