A new organ was installed in the cathedral in 1667, portions of which still are in use. The fleche of the cathedral, rebuilt four times, was finally removed in 1745. In the 18th century, the entire cathedral underwent a more serious transformation, to conform with new doctrines instituted by the Vatican. The Gothic altar from 1526 and the elaborate sculpted stone rood screen of the choir from the 13th century were removed. Portions of the rood screen are displayed today in the crypt. Many of the stained glass windows were replaced with white grisaille glass to provide more light. A new choir screen composed of nine wrought iron grills was put in placein 1760. and a new altar of white marble was installed 1767. The choir also received new carved choir stalls and a new marble floor.