Check out your local sub-culture nespaper. These are most easily found in cities with a million people or more and in college towns. Look in record stores, or boutique shops in the trendy parts of your town.
These newspapers are a gold mine. Chalk full of free events and nominally priced events, your summer will be overloaded with stuff to do. Many of the events are music or art oriented. The art ones, nicely enough, may include hor’dourves!
The free events are especially pervasive in the summer time. Take advantage of them and all the freebies that are handed out.