Previous commentators have maligned the La Clayette manuscript as a source of Ars Antiqua motets on three grounds: that its layout is not arranged for use in performance; that its notation is unsophisticated in its use of mensural forms; and that it is heavy with errors. This article offers a palaeographical account of the music fascicle and its methods of production, arguing that its layout was tailored to match the manuscript's literary portions, and was designed first by a text scribe specialising in the vernacular, which accounts for many of the supposed problems. The article describes the notator's ‘house style’ and his means of dealing with the text scribe's frequent errors, suggesting he was largely successful in transmitting usable musical readings. All this provides an opportunity to think through the historical possibilities for literate interaction with written polyphony in the thirteenth century. It is suggested that La Clayette was understood by its users as a tool with which a single reader could teach other, perhaps non-literate people to sing polytextual pieces.

This article examines the thinking of Guy of Saint-Denis about plainchant tones as formulated in his Tractatus de Tonis (c.1300), preserved as the final item in an anthology of texts that he prepared (British Library, MS Harley 281). It examines his attitude to each of the major theorists singled out in this anthology. It argues that Guy's approach to chant combines the practically oriented writings of Guido of Arezzo with the Aristotelian perspective formulated by Johannes de Grocheio, but takes that perspective a step further by reflecting on the ways different types of chant impact on the emotions. Guy was also much influenced by Peter of Auvergne, a philosopher in the Arts Faculty at Paris committed to developing the teaching of Thomas Aquinas. Careful corrections to the Tractatus in Harley 281 reflect this ongoing concern to refine his thinking, possibly stimulated by Jerome of Moravia. His core conviction is that chant modes each have an affective attribute, and need to be chosen according to the subject matter of the text being sung. Guy criticised the practice of choosing modes sequentially in liturgical offices composed by those he calls ‘moderns’. Guy argues his case by drawing on examples of chant from Saint-Denis. A case can be made, on palaeographic grounds, for identifying him with Guy of Châtres, abbot of Saint-Denis (1326–42) and author of a Sanctilogium that updates the traditional monastic martyrology by reference to more recent Dominican collections of saints' lives in order to make them more accessible for liturgical use.

Canonic techniques in the Trecento caccia reveal a wide spectrum of ostinato procedures ranging from brief cadence patterns to large-scale harmonic and/or melodic repetition schemes. The ostinato phenomenon is thus an important structural component of canonic technique in the caccia. This article examines these ostinato patterns in terms of a putative historical and structural transformation of the genre at the intersection of unwritten and written practices. Special emphasis is placed on the definition of the caccia from the anonymous Trecento treatise, Capitulum de vocibus applicatis verbis, and its correlation with the early layer of the caccia repertoire.