AURELIANUS of ROME. - A French monk who lived in the 9th century. His treatise *De musicae disciplina*, written around 830, of which two manuscripts survive—one in the Abbey of Saint-Amand and the other in the Laurentian Library in Florence—summarizes, in his own way, the doctrine of St. Augustine, Martianus Capella up to St. Bede, and aims to be a compendium of what a musician must know to distinguish himself from a mere singer. Among his somewhat confused explanations of neumes, he establishes the famous rule for the "triforia": *"trium ad instar manus verberantis facias celerem ictum"* (ch. xix). When he discusses the transposition of modes and certain formulas for psalms,
isolated figures of men holding scrolls and rods in their hands, as well as a figure of a naked woman holding an open veil with both hands, suggest non-orthodox beliefs, with which he may
it has not been possible to determine clearly whether he attributes them to fixed modality or not. However, it is interesting as a study for the classification of modes attributed to various antiphons, and it is a testimony to how this part of ancient modality should be studied before the medieval methodization.