You see dance audition (from classic "The chorus line" to recent reality shows), and they basically do the same.
Most dances and exercises are taught in this manner. You go to a dance class, and you move along the instructor for the (Zumba, salsa, cardio-whatever) class. For solo dances, you watch the instructor lift her right arm in a manner, then you do the same. You watch her step forward with right, you do the same.
This "tracing" is the most basic yet very tricky skill for dancing.
I wrote it simply, as if tracing were easy. Heck, no. Actually, very few people can do the tracing and do it well.
In other words, only people who can do the tracing well can succeed in a professional dance circle, coming through auditions. It's a part of essential skills for professional dancers.
But I am not writing this entry to professionals. I am writing to people who want to learn from the scratch or to improve your current skill.
Tracing helps. The same tracing skill can be used for pretty much all kind of physical activities. Dance, martial arts, sports, acting, .....tracing is a very useful skill.
Note: tracing in a partner dancing adds another layer to the tracing. But having skills for simpler solo tracing helps, too.
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Step 1. Find the "original".
You want to trace something. Then find an "original" with high quality. Originals with video footage serve best. High quality originals include great dancers or athletes (e.g. Michael Jackson, Bruce Lee, Muhammad Ali), or any other champions of the field of your choice.
I insist that you try to trace champions. It is not easy (or most likely impossible), but by trying, you'd appreciate their levels.
You'd have your "original". Choose one to work on. Then, watch it carefully.
When you watch a performance and get impressed, there is a reason. Try to describe the reason. "So smooth""So fast" "Very limber"."Perfectly synchronized""They are more committed in the moves""they move big""They are doing something I've never seen""They are so young!"....
There may be some reasons that you cannot trace. Probably you cannot be 5 years old again, or have limberness of a contortionist overnight. You can rate your possibility (or impossibility) of tracing. It's a part of appreciating the art, too.
You'd notice the "original" follow a certain rules. Be aware of it. Boxing follow the rules. Dancing, especially a partner dance, follow the rules (or basics for the dance) to some extent. If you are choosing a partner dance, you better know the rules.
For example, for exercise purpose, I tried to trace a classical boxing match "Sugar Ray Leonard vs Thomas Hearns 1 (1981)". You'd be surprised by the speed and slickness of their moves. You'd notice that you cannot move that fast if you are tense. You need to relax to move fast. Also, you might notice the flow of their motions.
Only when you try to trace the original yourself, you'd appreciate it better, or notice more critical details. You need to pay serious attention to trace.
[Sugar Ray Leonard vs Thomas Hearns 1 (1981)]
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That's it for the first step. You find your high-quality "original" that you like, watch, verbalize the reason why you like it or what makes the performance outstanding, and attempt to trace. Also know the rules that are applied to the performance of the original.
In some later entries, I'd write other steps, including "map your body""install motion capture software""segment them" etc.
Only when you know good performance, you can tell the difference between good performance and not-so-good performances. Finding good original is a part of educating yourself.