Two of Philadelphia’s main attractions are the Liberty Bell and the Large Glass by 20th century artist Marcel Duchamp, in the collection of the Philadelphia Museum of Art. Today, contemporary artist Christian Marclay has woven them together in an installation using music, video and gift-shop knick-knacks. He insists that the similarities between the Liberty Bell and Duchamp’s Large Glass only begin with the obvious fact that both are cracked. Joel Rose of Philadelphia station WHYY has the story.