" While the Gregorian chant in its afterlife has flourished as the authentic music of the Roman Church, its original character still remains in doubt. Not until the twentieth century did the Gregorian chant come back into its own. The old melodies had been mutilated into a monotonous plainchant to facilitate organ accompaniment. In 1889 the scholarly Benedictine monks of Solesmes in France undertook to rediscover the medieval practice. Their product was numerous volumes of “Gregorian chants” in a free-flowing nonrhythmic style. By 1903 they had recaptured the Gregorian chant to the satisfaction of Pope Pius X, himself a scholar of musical history, who established their versions of the Gregorian melodies by his encyclical motu proprio. But the rhythms still remain a puzzle. Pius X’s purified Gregorian chant banned the “theatrical style” of recitation, forbade the use of instruments, replaced women by boys in the church choir, and restricted the use of the organ. A Vatican Edition provided an authorized corpus of plainchant, which would prevail in the modern Catholic world. "

― Daniel J. Boorstin , The Creators: A History of Heroes of the Imagination