Berlin-based street artist Emess, who is well-known especially for his nice stencil collages, came up with a new project back in 2010 which is called City Music. This public art project is about acoustics in urban space, including beautiful sound-installations powered by urban wind power or even escalators!
What I like about those street artworks is that although the used technique is quite simple, the results are great! Hope to
see hear some more from Emess when he is back in town…