Thanks to those that commented.
Vesavekkuli - it is greatly rewarding for me to play in the park and at the Met. I do get great rewards - an not just financial, as you said.
The faces of the children, the enjoyment of the adults - many of whom wouldn't know Andres Segovia from Babe Ruth - that is my reward. And when I am in the ZONE, and I have a good, involved audience, well, that is the highest peak of my existence in this lifetime.