I was strolling down from Rocky Statue in Philladelphia to go back to my hotel. Suddenly I saw lights came out from several spots of the city. Later on, I knew that it was a public art by Rafael Lozano-Hemmer. It is a PUBLIC art since the lights actually are changed according to people’s voice frequencies. The voices can be submitted via website openairphilly.net (the websites is already closed now) or an i phone apps. Now, that was something. A public art that is controlled by public. Interesting, huh?