Aribo's "De musica", "Commentarius anonymus in Micrologum Guidonis Aretini" and Guido of Arezzo: textual correspondence and scholastic method

It is difficult to underestimate the influence exerted by Guido of Arezzo (d. c. 1040) on eleventh- and twelfth-century music theory. The large number of extant manuscripts containing his four treatises (Micrologus, Prologus in antiphonarium, Regule rithmice and Epistola ad Michahelem) points to the importance of his reputation and teaching for later generations of musicians. Guido's works - like those of other influential Italian authors - were widely disseminated in Germany: its great monastic libraries were quickly stocked with his music treatises, just as they were with Peter Damian's theological writings and dictaminal works by Alberic of Monte Cassino. Although German musicians held Guido in high regard, they did not receive his teaching uncritically. This was because he had said little about the theory of species and tetrachords that was central to music as it was studied in Germany. Starting with Herman of Reichenau (1013-54) - the first German author to address Guido's teaching - German musicians felt a need to interpret Guidonian theory in relation to their own.