Willie-O has a very good point. My freshman year in highschool, they had a local referendum arguing whether or not the local kids (read, us) could hang around the library after school. We didn't have another place to go. In February in New Hampshire, outside is not inviting. We'd hang about, certainly, talking but often reading as well. The problem was, we intimidated librarians, and they wanted us out. We couldn't even hang around outside the building. When we complained, they told us to go to the local rec center, a building with no furniture and no heat. (Again, NH in winter...) we spent an afternoon there, with people on the floor, and me on the enpty mantlepiece because it was slightly warmer... then went back to the library, and to hell with them. Kids have to go SOMEWHERE. They won't even trash it is they like it enough.
And, as Melani said, determined people will find somewhere, bandstand or not. ANYWHERE, in fact.