Artist and Busker Rights
A: Anywhere free speech is allowed, and you aren't blocking the flow of traffic on sidewalks, or door ways. Parks, beaches, sidewalks, any space that is public and is not charging a fee for the public to enter. Furthermore any private space that you have gained permission from the owner or venue.
Artist and Busker's rights: the blog
Ever wanted to learn how to defend your rights as a busker. This Blog is how you get there. This blog is full of information on 1st amendment protections for artists and buskers.