The story behind the pianos on Denver's 16th Street Mall: Keys to the City

DENVER, CO – MAY 09: The pianos are back! The pianos are back! The “Your Keys to the City”, public art program pianos along the 16th Street Mall have come out from winter hibernation in downtown Denver on Monday, May 09, 2016. This colorful piano is located between Tremont Place and Glenarm Place on the mall. (Photo by Cyrus McCrimmon/The Denver Post)