This is part of an installation that was commissioned by the city in 2005. The alley is a heavily used pedestrian thoroughfare and the city wanted to make it more scenic. I’ve walked it before and never noticed these things. They were produced by Jeremy B. Boyle and are supposed to include a constantly changing musical score…although I don’t think that part is working.
I read about this is the Art in Public Places book published by the Office of Public Art in Pittsburgh.
Another cool Pittsburgh blog that you should visit: