 Dom Pothier was appointed president of the newly created Pontifical Commission on the Vatican Edition of the Gregorian Liturgical Books by Pope Pius X in 1904.As chairman of this commission for the reconstitution of the music of the Roman Catholic Mass, Dom Pothier lived in Rome from 1904 till 1913.His "Liber Gradualis", 1883, marked the beginning of a reform in liturgical chant and was used as a basis for the "Gradual Vatican" which was published, under his responsibility, in 1908.