The reasons why people feel the need to motion and use signature moves when changing tone

Some singers twist their necks, shake their head, straighten their backs or raise their arms when changing tones when singing. Opera singers mostly display this motioning behavior, because they sing so loudly.
The tone of voice is made and controlled by the vocal cords. The vocal cords use expanding and contracting, hardening and softening, as well as thickening and thinning to sustain and produce these tones.
Regarding the action of expansion and contraction in which the vocal fold is composed of the vocal cords’ mucosa and the vocal cord muscles, these vocal cord muscles need to be supported to extend the muscles surrounding the larynx, because it cannot extend by itself.
The hardening and softening, thickening and thinning actions are also caused by the surrounding the laryngeal muscles.
However, it is a fact that no one can really know how to move and completely control these muscles.
Therefore, people tend to unconsciously as well a consciously motion by means of twisting the neck, shaking their head, and displaying hand movements to trigger their muscles moving.
This is similar to a baseball player moving their leg and foot before pitching or swinging a baseball bat, or an athlete performing a high jump by stepping back before flying forward to start the jump. These actions and motions trigger muscles by using their movement.
We as people try to find a trigger point, when singing, to moving muscles. This trigger is to acquire a precise tone after repeating. We tend to practice over and over again because we do not know how to change the tone of voice exactly.
Finally, singers can sing a song precisely after mastering it their way, using their practiced routine motions, as well as their emotional feelings when performing to harness and display the exact singing tone desired. Motion practice when singing can actually help increase continuity of the performance too, in turn adding confidence and satisfaction when successful.
However, if movement is too exaggerated or strange, the listener/audience might feel uncomfortable. Be mindful that excessive or too much repeated behavior in motioning during singing can have a negative impact depending on the degree displayed. Many successful singers have a signature move or motion that they display once or twice during a performance. Singers who perform a signature move or motion use the viewer’s yearning of seeing that move to their advantage, holding and captivating their audience’s attention for longer during a performance.

Blues singer