Traditional grade school in the USA consists mostly of intellectual activities. Within the study of academic subjects, students strive to achieve a mental understanding of the material. They prove their mastery of the material by being able to answer academic questions about the given subject. This reality is the cause of frustration for many of my academically bright public school students while studying the subject of instrumental music.
They approach the study of instrumental music as if it were a purely academic subject. They memorize the correct answer to questions like "How many beats is a half note held for?" and "What does the symbol P mean?" However, when their music contains a half note they do not hold it out for a full two beat, and when it contains the symbol P they do not play softly. Why is that?
The discord between their mental understanding of music and their application of that knowledge in musical performance is a result of their lack of treatment of instrumental music as a physical activity. I use illustrations from physical education class to try to relay this point to my students. For example, I could explain to them the proper way to shoot a basketball. They could understand every point about this technique and still have difficulty actually making a shot. The only way to truly master the skill is to physically practice it repeatedly. Their muscles need to feel the action while they observe the results of their technique. Then they can make adjustments based on the observed results until they finally master the skill.
Instrumental performance is a unique subject in that it is both academic and physical. There are many deep concepts to be studied within the field of music. Possessing an understanding of these concepts aids tremendously in one's ability to perform music. However, the leaning of our public school system toward purely academic studies causes many students to lack the ability to apply knowledge to physical performance. In addition, it is possible to perform a piece of music correctly through rote repetition with little understanding of the musical concepts that piece contains. It is impossible to perform a piece of music, however, without repetitious and effective practice.
This is why I say that playing music is 20% mental and 80% physical. In order to achieve a level of mastery within a musical performance, one must achieve a level of mastery of the physical activities associated with that performance. Wind players and singers need to know how to manipulate the air they supply to their instrument so that they can produce a beautiful and consistent tone regardless of range of pitch or dynamic level (or vowel/consonant being pronounced in the case of singers). String players need to be familiar with the proper feel of the bow as it moves across the string with excellent technique. Piano players need a physical awareness of the distance between keys and the exact force and technique needed to express various dynamics and emotions. These, and many other performance skills, can only be achieved through habitual practice.
There are those who think about music and those who play music. No matter how much knowledge you obtain about music, the only way to truly perform it skillfully is to maintain a regular practice routine. The more time one spends physically playing music on his instrument, the better he will become at playing music. That is why I say, "Playing music is 20% mental and 80% physical."