As music is an art form, it involves emotions and feelings, but more essentially, the soul. This means that whether a person is a musician or not, even artistic or not, they respond on that essential level to music. This is true for everyone in some capacity or another. So, when a musician performs for others, regardless of who comprises the audience, there will be some form of emotional response. This means that music has the potential to create major effects in others.
All artists have the urge to create aesthetically. The musician, whether a composer or a performer, has the primary urge to do this as a personal experience. It is a release for the artist. Just as the honeybee makes honey, the musician makes music. It's part of their inherent nature.
Despite this fact, the crucial thing to know is that the musician is not doing this just for his/her own amusement or enjoyment. Music is an art form. And art can be considered art only so long as it is communicated to others.
The misconception is that art is done strictly for one's own enjoyment. While this can certainly be therapeutic or pleasurable, the fact of the matter is that if one creates aesthetically only for his/her own personal indulgence, it remains but a hobby. The artist or musician is becoming the effect of his/her cause. To be art, it must create an effect on others.
Imagine your favorite musicians. Consider that these artists never performed for anyone but themselves. Their art would have zero effect on you or other fans. In fact, they would have zero fans. In fact, you would have no clue that they even existed. That you have heard their message aesthetically, what effect did it create on you?
Again, just as the honeybee makes honey, the musician makes music. However, the honeybee isn't making honey just for itself; it's making it for the benefit of its hive, not to mention that other animals and humans also benefit from it. In the same way, the musician is creating music as an effect upon others. He/she is communicating aesthetically. True, it's enjoyable, but it's not just a hobby; its art. And that involves the communication to and elicited participation of others.
It's an ongoing interchange of energy. The good musician's performance is intoxicating to the listener. The waves of energy play upon each other and grow. Incidentally, this is also what gives music its humanitarian aspect. It can create such positive feelings that it can result in human betterment. This is also why music students are encouraged to give student recitals. This is important to do regardless of the size of the audience, but just as long as there is an actual audience.
To perform for others is what it's all about. It's a joy to use such power and ability to inspire others and thus elevate the world with higher sophistication.