Practice Procedures: Part 17: External Versus Internal Forces
April 2, 2017
When a movement of a part of the body comes as a result of the muscles in and around that part, I call the force generated ‘internal’. Alternatively if the left hand takes hold of the right hand and causes the latter to move in some way, the force applied to the right hand is ‘external’ to the point on the right hand where the force is applied.
The motion in the right hand now has a very different physically sensed quality than a force coming from the right side of the body.
The advantage of one hand moving the other is that the hand being moved feels stronger, more agile in its motion, than it would using only its own muscular initiative.
Any point on the playing mechanism can be the point of application for an external force that imparts motion to the point.
The objection might be made that, in performance, one hand cannot take hold of the other when both hands are on the keyboard. The objection is overcome through the existence of “mirror neurons”. Here is a definition that shows up on google.com when I search for “mirror neuron”.
“A mirror neuron is a neuron that fires both when an animal acts and when the animal observes the same action performed by another. Thus, the neuron “mirrors” the behavior of the other, as though the observer were itself acting.” Thank you, to Google.
As a corollary to this definition, even if the model for the movement is not visual but tactile, in other words, even without the actual intervention of the left hand to cause the motion in the right hand, we can ‘recreate” the sensation that occurred in the right hand when it was physically being moved by the left hand.
Rather than another part of the pianist’s body, sometimes the teacher will create the external force to move the student’s right hand. The only advantage of the teacher making the motion rather than another part of the student’s body, is that the teacher may have a more experienced and refined sense of when, where and how, to apply the force. But the student can still repeat the action, in all its details, because they have just experienced in their bodies what this combination of motions feels like.