Taking a lifetime of work to complete, Bragers composed his organ accompaniment series to help implement Pope St. Pius X's motu proprio on the reform of sacred music (Tra le Sollecitudini, 1903). His series (published over the course of many years) was well received, considered to be definitive and preferred by organists to the earlier series by Henri Potiron. Le Propre du Temps: Gregorian Chant Accompaniment.