Motor Cortex
The motor cortex is primarily concerned with voluntary movements. Every part of the body is directed in the primary motor cortex, and these representations are arranged somatotopically — the foot is next to the leg which is next to the trunk which is next to the arm and the hand. The amount of brain matter devoted to any particular body part represents the amount of control that the primary motor cortex has over that body part. For example, a lot of cortical space is required to control the complex movements of the hand and fingers, and these body parts take up a larger amount of brain matter in the motor cortex than the hips or thighs, meaning their muscle patterns are more complex.
How does this relate to music?
High-groove music has been shown to excite the motor system. It is more receptive to musicians, which could be from the tight auditory–motor links in musicians.In a study, non-musicians were less receptive to high-groove music than musicians.high-groove music engages the motor system, and previous training . Music with a strong groove activates the motor system.