Anonymous IV (fl. 12501280), music theorist, may have been a monk of Bury St Edmunds. He studied (or at least lived) in Paris, and, like many in contact with contemporary music there, he disseminated knowledge about the new styles when he returned to his native land. His treatise, De mensuris et discantu, was first edited by the French musicologist C.-E.-H. de Coussemaker, who placed it fourth in a series of anonymous writings; hence the name by which he is known. It gives unusually verbose accounts of standard topics included in thirteenth-century music treatises: rhythmic notation, consonance and dissonance, and polyphonic genres and style. However, the true value of Anonymous IV lies in his fondness for deviating from the main topic and drawing examples from living musicians and named compositions. Thus, exceptionally in such a work, actual composers, notators, and singers are mentioned; musical practices in various geographical locations are observed; and musical genres and the manner of their performance are commented upon. Because Anonymous IV is so specific, Friedrich Ludwig, at the beginning of the twentieth century, was able to match the discussions with surviving thirteenth-century music manuscripts of the so-called Notre Dame school, thus identifying key aspects of genre and notation.
In De mensuris et discantu Magister Leoninus (fl. c.11601190) is noted as having composed a cycle of settings of mass and office responsories in organum, an older, unmeasured style of composition, prevalent until the turn of the thirteenth century, in which a rhapsodic upper voice weaves elaborate configurations against a slow-moving lower voice. Magister Perotinus (fl. c.1200), on the other hand, has revised this by replacing some parts in the taut new rhythmic style. Methods of notating the new rhythms are given; like other parts of the treatise, this commentary depends heavily on that of the mid-thirteenth-century Paris master Johannes de Garlandia. Conducti, organa, and motetsthen the chief genresare identified by name; some are ascribed to Leoninus or Perotinus. Efforts to match these two composers with known members of the personnel of Notre Dame Cathedral have been only dubiously successful.
Anonymous IV describes aspects of English practice. Intervals of a third, considered dissonant in France, are in certain lands like in England, in the region which is called Westcuntre [thought] the best concords (Music Treatise of Anonymous IV, 69). He discusses English notation, mentioning special diamond-shaped notes called elmuarifa or elmuahim. He also comments: There were good singers in England … like Master Iohannes Filius Dei, or Makeblite in Winchester and Blakesmit in the court of the last king, Lord Henry [III] (ibid., 44).
Der Musiktraktat des Anonymous 4, ed. F. Reckow, 2 vols. (1967) · The music treatise of Anonymous IV: a new translation, trans. J. Yudkin (1985) · C. E. H. de Coussemaker, Scriptorum de musica medii aevi, 4 vols. (186476); repr. (Hildesheim, 1963), vol. 1 · F. Ludwig, Die geistliche nichtliturgische und weltliche einstimmige und die mehrstimmige Musik des Mittelalters bis zum Anfang des 15. Jahrhunderts, Handbuch der Musikgeschichte, ed. G. Adler (Frankfurt am Main, 1924), 157295
BL, Royal MS 12 C.vi, fols. 59r80v
BL, Cotton MS Tiberius B.ix, fols. 215r224r
BL, Add. MS 4909