Hi Guest,
There are very few absolutes in dancing, since differences in context call for differences in solution. So I tend to avoid the word "always", at least without qualifying it.
In the case of CBMP, the broad, all-encompassing answer to your question is No. There are circumstances where one partner may step in CBMP while the other does not. Step 5 of a Natural Spin Turn is a good example of that.
But if we take your example of step 1 of Spin Turn and narrow the parameters down to just outside partner steps, *now* I can comfortably say yes, pretty much always. There may be some exception, but if there is, it's escaping me at the moment. If a step is taken outside partner, I can almost guarantee both man and lady must step in CBMP.
Of course, since you're quoting book technique, I'm making some assumptions about context, e.g. closed body contact, syllabus Int'l style, etc. It's quite easy to step outside partner on separate tracks if you don't have to maintain a proper standard hold. Once the position, frame and spacing are flexible, all manner of exceptions could theoretically be made. In American style, reasons to make exceptions to such rules do crop up more frequently. But in general, we will tend to follow the same set of constructs, even when it's not 100% necessary.
At any rate, I digress. Back to the simple answer: Yes, the lady's step 1 of a Natural Turn when commenced with man outside partner is also in CBMP.
Regards,
Jonathan
