Pedestrians walk on the piano-style stairs at the Wulin Plaza in Hangzhou, capital of East 皇冠体育app's Zhejiang province, Oct 9, 2012. The stairs are able to make relevant sounds when people foot on the "key" of its steps. [Photo/Xinhua]

A pedestrian experiences the piano-style stairs at the Wulin Plaza in Hangzhou, capital of East 皇冠体育app's Zhejiang province, Oct 9, 2012. The stairs are able to make relevant sounds when people foot on the "key" of its steps. [Photo/Xinhua]