The short answer is – when you throughly understand that particular principle yourself, both intellectually and in your own hands, when it is part of your playing. Put on your own oxygen mask before helping others.
Unfortunately, there have been many cases of teachers attending a Taubman workshop or symposium and claiming to be a Taubman teacher. As anyone who has read through the requirements of the Golandsky Institute Professional Training Program can attest, training to be a certified teacher is rigorous, and with good reason. There are infinite combinations of choreographic movement at the piano, and just as many combinations of problematic and also interwoven healthy movement patterns a student can bring with them. Being a Taubman teacher is a huge responsibility; knowing what to leave alone, what to encourage, how to prioritise what can help someone the most at that moment in time, how to skilfully help someone smoothly transition from injury to healthy playing.
On the other hand, I know of several teachers who have a wealth of Taubman lessons and experience, but are so worried about teaching the work properly that they don’t share their knowledge at all in their teaching. To me, that is such a shame.
Having said this, please don’t teach rotation unless you have had a series of lessons with a trained Taubman teacher. When I work with students who were taught rotation by someone who has never had Taubman lessons themselves, the results are often disastrous. Like all incoordinate movements, incorrect rotation can create more problems, including pain and further injury. It is possible to rotate with a low wrist, to rotate and stretch, rotate and curl, rotate and squeeze into the keys, rotate and twist etc. Yet these all violate the fundamental Taubman principle of the fingers, hand and forearm working together as a synchronized unit. Playing in this way cannot be called Taubman work.
So, teach what makes sense to you, and what you have personally experienced to be healthy and right. There’s so much you can do without teaching rotation. Even correcting a seat height or a low wrist can already inspire many more healthy movements. As Edna Golandsky once told me, “Right breeds right”. If your instinct tells you a student’s fingering looks awkward or stretchy to you, get in there and find another alternative. You might find something better later on, but for right now, just rid of that awkward moment. Organizational skills, such as grouping, immediately make sense to people and can make a huge and immediate difference. Start looking for the closest note in leaps, work in the interdependence between the hands. Don’t withhold what you know in teaching children, they need this information from the beginning. Adults who have retrained are often amazed at how fast children learn, often in contrast to their own experience of retraining. The logic makes total sense to children, if taught well.
If you do go on to pursue more in-depth Taubman training, you will then gradually and intimately learn to know the subtleties and depth within each of these fundamental principles: how the alignment of a particular chord varies over different registers, the exact placement on each key for a passage to fit like a glove, even the slight tweaks in bench height within what is right. But start somewhere, where you are, and with what you know. Then, there’s more waiting for you, should you choose to pursue the wealth of knowledge that awaits.