According to this website, “A public performance is considered under many national laws to include any performance of a work at a place where the public is or can be present; or at a place not open to the public, but where a substantial number of persons outside the normal circle of a family and its close acquaintances is present. The right of public performance entitles the author or other copyright owner to authorize live performances of a work, such as a play in a theater, or an orchestra performance of a symphony in a concert hall. Public performance also includes performance by means of recordings. Thus a musical work is considered publicly performed when a sound recording of that work, or phonogram, is played over amplification equipment, for example in a discotheque, airplane, or shopping mall.”  Until reading this, I had never considered publicly playing a song to be considered a public performance.  I guess this means that with the weather warming up, people who play music on the quad need to get some kind of permission from the artist to play their music.