Cavaillé-Coll's Monumental Organ Project for Saint Peter's, Rome: Bigger Than Them All, by Ronald Ebrecht, tells the engrossing story of Aristide Cavaillé-Coll's quest to build the largest-ever mechanical-action organ in the biggest church at the time. Cavaillé-Coll is often referred to as the greatest organ builder of all time, and his efforts to build this impressive organ were complicated by intricate, intractable problems. Saint-Peter's Square, now a part of the Vatican City State, was then part of the newly-united Italy, which had just deposed the pope as ruler of the center of Italy and taken over the papal lands. It was a part of the Italian state so hotly contested that the Italian Republicans would not accept an organ hanged from the basilica wall, lest the nearby, oft-disputed boundary shift. Before, or since, has the music sphere ever provoked such a question that could bring nations to swords?