An observation - one which my present teacher first made me aware of, and I have seen since then more than once when looking at various on-line lessons:
What a teacher presents may not actually be what that teacher is doing. Sometimes the teacher thinks she is doing it, but isn't. At other times she may deliberately leave out other elements, in order to isolate what she is concentrating on. When she plays, she uses all elements, but the student who diligently follows instructions won't. One thing I have learned to do when watching such things (as advised) is "Watch when the person stops teaching and demonstrating a given technique, and plays naturally. What does she really do? How is it different?" It can be quite revealing.
Some examples at random:
- A teacher is showing in isolation what is done with the fingers, or hand. He then plays, demonstrating that thing in isolation. If you really watch, however, you'll see traces of subtle movement in the wrist, arm, etc. Then when he plays music involving similar things, suddenly there is a host of other movements. The problem with this kind of instruction or demonstrating is that the whole body works together, and if you try to isolate one thing, you end up locking up other parts of your body. The teacher will still keep these things free somewhat, but the student won't.
- I watched a series of on-line lessons that one can subscribe to for free. The emphasis was on forearm, wrist, hand etc., rotation, up-down and similar. One particular piece was demonstrated and taught for the sake of this. By chance, that teacher used the same piece to teach pedal, and this time the camera was set at a full body view angle, in order to show the piece. This time one could see how he shifted body weight, and how many of those movements in the forearms (as per the original demo) actually originated as far down as the hips with fluid body movements that flowed into the arms, hands etc.
I've run into a thing which I'll call "additive" for lack of a name for it. Here a teacher will teach one isolated thing while cutting out the others, and over time add the other things. My example is from violin - I hope this is ok. For changing from one string to the other, many teach beginners to raise their elbow to new heights at the shoulder. In actual fact, to varying degrees the arm at the shoulder, the forearm at the elbow, the hand at the wrist, and the fingers at the knuckles, all play a role in varying proportions. a) One set of teachers have students use only the crude arm at shoulder way, and give repertoire that supports this limited motion - as the student advances, the forearm at elbow is added, along with repertoire needing this - and so on. I call this "additive". b) Another set doesn't create these restrictions, allows for experimentation, and says that everything has to be able to move to some degree, and how much for each varies according to the music. They encourage natural use of the body, exploration etc.
The problem with the "additive" system is that if it is normal for everything to be free to move at least a little bit, and as a student you diligently isolate that one thing that is "allowed" to move, you are also locking up and tensing the body. Whether you can magically free up these parts later on, as more is "added" is an open question. I believe that back then I learned in the "additive" way.
Following instructions is a tricky business. If a teacher is aware, able to observe, rather than following some handed down formula, then the teacher will be adapting the teaching according to the student and the student's needs. This includes observing the student, seeing whether it's working, whether the instructions are causing problems or helping, and adjusting accordingly.
The danger is also those teachers who have an idea of what is "supposed to" be done, according to how they have been taught. For a student it's tricky business.