 Above the entrance of the Chapel of the Corporal stands the cathedral's large organ, containing 5,585 pipes and originally designed by Ippolito Scalza and Bernardino Benvenuti in the fifteenth century before being redesigned in 1913 and 1975.Scalza's other major contribution to the church is the large Pietà he sculpted in 1579. it took him eight years the carve the four figures in this imposing marble group.The large stained-glass quadrifore window in the apse was made between 1328 and 1334 by Giovanni di Bonino, a glass master from Assisi.