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
Vatican City within Italy, its military defence is provided by the Italian armed forces. However, there is no formal defence treaty with Italy, as the Vatican City is a neutral state. Vatican City has no armed forces of its own, although the Swiss Guard is a military corps of the Holy See responsible for the personal security of the Pope, and resident in the state. Soldiers of the Swiss Guard are entitled to hold Vatican City State passports and nationality. Swiss mercenaries were historically recruited by Popes as part of an army for the Papal States, and the Pontifical Swiss Guard was