A short while back, a student and I attended a large group training weekend. We had a lot of fun, generally speaking. I like my student, who has worked very hard and done quite well in terms of advancement, but he sometimes (as a lot of beginners seem to do), focuses on details when the big picture is more important. For example, every now and then, he will ask about the exact angle for a kamae, as though I am carrying around a protractor. At times like this I (or one of the other sempai) will make fun of him in a gentle way, and I will remind him that maintaining a flexible mind when it comes to kata is a good thing.
By flexibility, I don't mean changing the kata to suit oneself (which is not good form for koryu budo). Instead, for example, when doing a partner kata with a jodoka a foot taller than me (which happens frequently in America), if the tachi side's target for a cut is his midsection, I might cut for the upper thigh instead. Same cut, same technique in response (though perhaps a little closer to the floor). It makes more sense for me to do that than to try to cut for a target I can't reach. Most importantly (for koryu training purposes), the kata is essentially unchanged.
So - halfway through our training weekend, I had a few minutes with my student (we were at different levels and hence in different training groups), and he mentioned to me, with some distress, that one of the instructors was "changing" some aspects of the kata; and that some of the kata he was reviewing were "different." Not having much time for discussion, I assured him we could go over things the following week at our regular okeiko.
Kata are not hoary, rigid sets of movements. Neither are they free-for-alls. The first gasshuku I attended in Japan, senior, menkyo-level students would sometimes stand around in little groups, debating this or that aspect of a kata. The discussions could become very involved, until the lead teacher would show up. Someone in the group would explain the discussion. The teacher's response was always the same: "Do it like this." That would settle the argument. But only for the time being. The debate would resume at another practice, at another time.
These discussions were not subversive disagreements. The speakers, all 30-40-year practitioners, were considering interpretations of what they were doing in a given kata. The ideas were often based on aspects of timing, not of specific techniques. Do you suki tachi to push him back to keep him from attacking further? Or do you let him establish a retreating step and "help him along" with the suki to increase the distance between you? In both cases, the technique was still a suki, still occurring at the same place in the sequence of movements. The difference lay in the interpretation.
It had not occurred to my student, but we did have the same instructors for the training weekend. They were all rather admirably on the same page for the actual kata we were training in, but, not surprisingly, some of the ideas behind the techniques varied from time to time, and from person to person. Having been through this experience before, it was not difficult to handle my student's doubts about the kata when we had our next regular okeiko.
The "differences" he noted were not really different; I pointed out. The kata themselves were unchanged. What to do with the different interpretations? Absorb them, I said. When an instructor suggested a different motivation for a technique, try it out. If the next instructor had a different idea, try that one too. What he would come to find out is that neither idea was necessarily wrong (if it was, that would be a separate problem). Instead, the different interpretations add depth to the understanding of the kata. Moreover, the more we try these different interpretations under the guidance of seniors and teachers, the more we can adapt to different training partners. As weird as it seems, I do sometimes get to practice with someone close to my size. When that happens, the original target for my cut on the tachi side rematerializes. Without maintaining that flexibility of mind, I would be aiming too low for practicality in the name of blindly following the interpretation I had set for myself.
Kata are not an end in themselves, and they are not museum pieces. They are pedagogical methods that only become useful as they are applied in different situations with different training partners. Recognizing when to react one way or another when training, even in koryu kata, enriches and enlarges our practice.