The writer who would trace the history of the modern musical mass has a task very different from that which meets the historian of the mediaeval period. In the latter case, as has already been shown, generalization is comparatively easy, for we deal with music in which differences of nationality and individual style hardly appear. The modern Catholic music, on the other hand, follows the currents that shape the course of secular music. Where secular music becomes formalized, as in the early Italian opera, religious music tends to sink into a similar routine. When, on the other hand, men of commanding genius, such as Beethoven, Berlioz, Liszt, Verdi, contribute works of a purely individual stamp to the general development of musical art, their church compositions form no exception, but are likewise sharply differentiated from others of the same class. The influence of nationality makes itself felt—there is a style characteristic of Italy, another of South Germany and Austria, another of Paris, although these distinctions tend to disappear under the solvent of modern cosmopolitanism. The Church does not positively dictate any particular norm or method, and hence local tendencies have run their course almost unchecked. Catholic music has shared all the fluctuations of European taste. The levity of the eighteenth and early part of the nineteenth centuries was as apparent in the mass as in the opera. The uplift in musical culture during the last one hundred years has carried church composition along with it, so that almost all the works produced since Palestrina, of which the Church has most reason to be proud, belong to the nineteenth century. One of the ultimate results of the modern license in style and the tendency toward individual expression is the custom of writing masses as free compositions rather than for liturgic uses, and of performing them in public halls or theatres in the same manner as oratorios. Mozart wrote his Requiem to the order of a private patron. Beethoven’s Missa Solemnis, not being ready when wanted for a consecration ceremony, outgrew the dimensions of a service mass altogether, and was finished without any liturgic purpose in view. Cherubini’s mass in D minor and Liszt’s Gran Mass were each composed for a single occasion, and both of them, like the Requiems of Berlioz and Dvořák, although often heard in concerts, have but very rarely been performed in church worship. Masses have even been written by Protestants, such as Bach, Schumann, Hauptmann, Richter, and Becker. Masses that are written under the same impulse as ordinary concert and dramatic works easily violate the ecclesiastical spirit, and pass into the category of religious works that are non-churchly, and it may often seem necessary to class them with cantatas on account of their semi-dramatic tone. In such productions as Bach’s B minor Mass, Beethoven’s Missa Solemnis, and Berlioz’s Requiem we have works that