Most people enjoy music. The ability to make music exponentially increases this enjoyment. Many adults often find themselves regretting not having taken (or having quit lessons).
This is a good way to establish structure and discipline, which children NEED but do not WANT. This INTERNAL discipline is stronger and longer lasting than any externally-forced discipline.
The concentration required in learning music carries over into learning other subjects.
For children, good piano lessons can help establish a solid educational foundation which will make learning almost anything fun.
Recent studies have shown that, for both children and adults, playing a musical instrument can reduce stress.
The phrase "think outside the box" has been used in the bussiness world to denote thinking beyond the conventional, the mundane, the obvious. Musical education contributes greatly to Thinking and Interpretation, necessities to success.
Learning effective practice skills aids the child in developing patience.
Listening - the active counterpart to passive hearing can sometimes reveal hidden meanings otherwise lost. Knowing how to listen can also increase patience.
Many adults have terrible fear of public speaking (for some, this fear is second only to death!), but may be required to do so. Learning to play in front of a small and supportive audience helps in reducing this fear (in some circumstances diagnosed as Social Anxiety Disorder).
Many people suffer from some form of shyness. Interacting with a music teacher and other students can significantly help in overcoming shyness.
Of all positive emotions, very high ranking is the satisfaction of achievement. The greater the challenge, the greater the satisfaction. Music has a nearly unlimited set of challenges, and the equally rewarding sense of achievement.
Recent studies show that, together with school work, music lessons have contributed to increase of IQ and school grades.
Through all of the above, children develop confidence and poise that will be useful in dealing with many situations in life.