Music of Vatican City a result, reformers like Palestrina revised the rules behind Gregorian chanting, which were printed by the Medici Press in Rome; these reforms continued to be followed to the present day. A traditional musical instrument was the pipe organ. After the end of the Papal States the Popes' ability to sponsor composers and musicians waned. However it did not end entirely nor did interest in the subject. Pope Pius X and Pope Pius XII both wrote on the subject. In modern times John Harbison and Gilbert Levine have composed or conducted for the Vatican. Although not of the Vatican a Christmas
Prisoner in the Vatican or from inside the basilica, and papal coronations were instead held at the Sistine Chapel. The period ended in 1929, when the Lateran Treaty created the modern state of Vatican City. The 13 May 1871 Italian Law of Guarantees, passed eight months after the capture of Rome, was an attempt to solve the problem by making the pope a subject of the Kingdom of Italy, not an independent sovereign, while guaranteeing him certain honors similar to those given to the king and the right to send and receive ambassadors. The popes—Pius IX (died 1878) and his successors Leo XIII (reigned