Yes, because arts make you free, freedom gives you happiness, and happy people are the most able to develop themselves and others.
What does it mean in case of children? Playing is a way of existence for children, demanding free and independent decisions; which makes them feel good, free of pressure and obligations, just like when it comes to arts. Practicing arts (music, dance, handicraft) or any other kind of creative activity, manifests with an emotional charge, involving the right brain. Enjoying arts induces a similar kind of emotional charge as games, in which children get rid of their inhibitions, and obliviously enchanted, they get a step farther from reality, into a different dimension, in which they can pass themselves over for everything they see or hear.
It's worth to observe the children and their experiences at such events. If they had a great time, they get richer mentally.