Pratice Technique 29: Motions Within Motions.
April 25, 2017
Motions within motions.
Can a single motion be directed left and right, or up and down, at the same time? The answer is yes, by combining the two motions into one overall motion.
An analogy from mathematics would be a ‘sine wave’. It travels vertically up and down at the same time it travels horizontally left to right.
An analogy from astronomy would be Ptolemy’s system of “epicycles” to explain why Mars, for instance, seemed to travel slowly eastward in the night sky except at certain times when it slowed up, reversed direction and traveled westward, only to eventually resume its eastward drift.
For us as pianists smaller circles within larger circles can imitate the motion of Mars but measured in seconds and not months as in the astronomical case. Our own system of epicycles.
Because of the wealth of joints, or points of articulation in our skeleton, almost any two parts of the body can travel in opposite directions under certain circumstances.
Why is this complexity of motion important to us? It is because when we seek out body motions to facilitate a certain sequence of pitches with a certain sequence of fingers, a single motion, at a single rate, in a single direction, often can only poorly approximate the details in the score.
Take a simple example. The right hand plays:
c e b d a c g b f a e g
using fingers 1 and 3 in alternation.
A rightwards directed, clockwise rotation in the forearms facilitates the motion between two notes that are separated by the rising thirds. Then there is also the downwards directed motion, c – b – a – g – f.
The question arises whether we should allow the forearm rotation facilitate the descending fourths ( e b d a c g, … ) as well as the ascending motions in thirds, simply by changing direction of the rotation back and forth. If we do so, then the entire burden of the zizzag pitch outline is on the forearm rotation. A better solution is to blend together two different types of motions. We consciously focus the rotational motion on the ascending thirds. Then we can allow a gradual, steady drift leftwards of the entire arm, articulating at the shoulder, to handle the more spaced out descending seconds. All that is left to do is harmonize the two motions, specifically with regard to what percentage of the motion is forearm directed and which part is arm directed.