If you haven't heard of Random Acts of Culture, it is a program which is striving to have 1,000 performances of culture and art randomly, throughout the country. They have done 379 to date. Here are a couple of recent ones:
29 Members of Seraphic Fire (a group of singers) serenade a mall crowd:
Here 7 performers from Florida Grand Opera surprised people at Miami International Airport:
I am still waiting to see one of these myself. It would make my day.