Like other elements used in modern piano technique, the concept of shaping is not new.
Liszt first documented shaping and observed Chopin's barely noticeable wave-like wrist movements.
This contrasted with the standard rigid wrists and high finger action of that time and noted Chopin's beautiful tone.
These "cycloid" motions became an integral component of Liszt's playing and pedagogy in his later life.
In traditional teaching, shaping from the wrist, or a flexible wrist is often taught. However, in modern piano technique, shaping is a lateral, elliptical forearm movement across a group of notes, passively moving the wrist and the upper arm in response.
If the wrist initiates movement, broken fulcrums and alignment result, depriving the playing finger of the forearm's support.
There are two families of shapes:
the undershape, and
the overshape
Question: How can "cycloid" motions of the fingers, hand, and forearm be described geometrically?
The term "cycloid" refers to the geometric path that a fixed point on a wheel's circumference traces as the wheel rolls without slipping along a straight line. In the context of human anatomy, the term "cycloid motions" is often used to describe certain movements of the fingers, hand, and forearm that resemble this geometric trajectory. This article aims to describe these movements in a rigorous geometric context.
Finger Movement:
The "cycloid motion" of a finger can be visualized by considering the finger to be a rigid line segment that is 'rolling' along the surface of an imaginary sphere. This is comparable to how a straight line segment would trace a cycloid path if it were 'rolling' along a plane without slipping.
This movement can be described as a combination of rotation and translation along the curved surface. The movement starts with the finger flexed and gradually extends, mimicking the progressive revelation of a line as a cycloid is traced. The contact point between the finger and the sphere's surface would represent the tracing point on the rolling line.
Hand Movement:
To describe the "cycloid motion" of the hand, one could picture the hand as a flat plane or disc moving in a manner similar to a rolling wheel along a surface. The path followed by a fixed point on the edge of the hand will describe a cycloid in three-dimensional space.
As with finger motion, this involves a combination of rotation and translation. The hand starts with the wrist flexed and gradually extends, following a path that appears like a series of loops or arches, much like the curve described by a cycloid.
Forearm Movement:
In terms of the forearm, envision the forearm as a cylinder or elongated disc, with one end at the elbow and the other end free. Similar to the hand, as the forearm moves in a rotational manner about the elbow joint, a fixed point on the edge of the forearm will trace out a cycloid-like path.
This movement involves not only the rotation about the elbow joint but also the translation of the entire arm. The forearm starts with the elbow flexed and gradually extends, following a path that represents the tracing of the cycloid curve in three-dimensional space.
The geometric interpretation of these "cycloid motions" gives an insightful framework for understanding and analyzing the complex movements of the human body. It is crucial, however, to remember that real human motion is more complex, considering factors like joint constraints, the flexibility of tissues, and the coordination between different body parts. Despite these complexities, the cycloid motion model provides a useful baseline for understanding the overall motion patterns of the fingers, hand, and forearm.
A cycloid generated by a rolling circle
Whether a shape is an undershape or overshape can be influenced by
fingering,
in and out movement in the depth dimension, or
changes of direction.
The width and depth of the shape varies according to the situation.
"I've experienced unwanted accents dissolving through my arm being in the right place, and fatigue evaporating when excessive
shaping was minimized".
