Singers from the area south of Rome kept the Gregorian repertory received in the ninth century, including a few early tropes and proses, and their traditional Old Beneventan repertory alive side by side with remarkable consistency in oral tradition for nearly two hundred years. This might explain why the received Gregorian repertory retained its archaic traits in Benevento rather than in northern Europe. For the ‘new music’ of the tenth and eleventh centuries, mostly locally composed tropes, proses, and Latin Kyrieleison, south Italian singers adopted the musical surface of Gregorian chant, albeit Italianised (that is, moving largely in stepwise motion), but for the large-scale formal structures they harked back to the nearly obsessive repetition of extended passages that are the hallmark of Old Beneventan.

This article reports the discovery of an early fourteenth-century manuscript fragment (two small snippets from the same folio) of Castilian origin. One side of the original folio contained a monophonic piece in Ars Nova notation whose text has been identified as Mozarabic preces, a musical repertoire that was suposed to lack written transmission from the twelfth to the early sixteenth centuries. The fragment thus throws new light on the survival of the Mozarabic rite through the late Middle Ages. The backside of the folio contains music written in an old mensural system based on undifferentiated semibreves and puncta divisionis. In this regard, the manuscript may represent the earliest known Spanish source to employ the Petronian system described in the mensural treatise in Barcelona Cathedral (misc. 23). The study includes a detailed codicological examination of the manuscript (including the digital restoration of a palimpsest), transcriptions and musical analysis.

By all appearances, the advent of a full-fledged hexachordal system in the late thirteenth century marked the culmination of a radical reconceptualisation of diatonic space that had begun over two centuries earlier with Guido of Arezzo's introduction of the syllables ut re mi fa sol la as an aid to sight-singing. An early witness of the new diatonic configuration is Johannes de Garlandia's Introductio musicae planae (c.1275), which presents the three proprietates per b quadro, per natura and per b molle as a fundamental articulation of the gamut that is necessary for conveying the intervallic distances between the diatonic pitches.

A contextual evaluation of the theory of the proprietates, however, indicates that the hexachordal parsing of the gamut was not meant to establish the major sixth as the regulative paradigm of diatonic space (i.e. as a normative scale), but was rather in line with the earlier understanding of the ut-la syllables as an optional aid for singing. The development of hexachordal theory was in fact an implicit confirmation of the heptachordal structure of the gamut that had been in place since around the year 1000 (and arguably earlier), when the cycle of seven A–G letters was first used to label the constituent pitches of the octave.