If you want to create a work of art that is unified in its mood and consistent in its structure … [then] this is only possible through the inspiration by a poetical idea, whether or not it be introduced as a programme. I consider it a legitimate artistic method to create a correspondingly new form for every new subject. … Of course, purely formalistic, Hanslickian music-making will no longer be possible, and we cannot have any more random patterns, that mean nothing either to the composer or the listener.

It is possible that some motet composers were drawn to a hyperbolized and even transcendentalized conception of the materials of composition; such attitudes have been too common among the composers of the twentieth century for us to deny them to those of the fourteenth.

Many contend that the reception of medieval music in modern times says more about the society remaking the Middle Ages in its own image than it does about the Middle Ages. The revival of interest in medieval music since the eighteenth century, though entertaining as a story, is, one might argue, irrelevant to any current attempt to come to grips with the function, social context, and compositional history of this music in its own time. But that is what I am going to attempt here. I want to take useful historical analogies – of any vintage – and use them to reveal some unexpected things, not about the present, but about the past.

Nineteenth-century editors took Machaut's hybrid narrative Voir dit literally, as a love story, a fact we may either decry or find amusing, but Machaut himself anticipated this reception. As Deborah McGrady has shown, the courtly public he depicted in the poem received his ongoing project literally as well. Regardless of the range of motivations that may have guided the poet's creation, he knew, for better or for worse, that his courtly consumers prized the story's entertainment value above all, and so it should not astonish us that the exact same interpretation resonated when the work re-emerged in the nineteenth century. In spite of the superiority we feel as regards scholarly matters, the nineteenth-century reception actually remains a valid facet of the work.

SCHOLARS TODAY generally agree that ‘isorhythm’ ought to mean what it says, a term describing segments of music literally exhibiting the ‘same rhythm’, duration for duration. This is the lesson of Margaret Bent's influential 2008 article ‘What is Isorhythm?’ By then, the literal sense of the term had already been normal usage in the work of many scholars, including, besides Bent herself, Ernest Sanders and Daniel Leech-Wilkinson. As a designation of genre, however, ‘the isorhythmic motet’, a looser and vastly more inclusive usage was still generally accepted, and Bent's call for strict consistency between the nominal and adjectival forms of the term effectively limits its application as a generic designation to a small and incohesive assemblage of works, leaving the category without historical relevance. As compensation for a focused reinterpretation of this and many other terms, Bent offers a new terminological precision capable of distinguishing procedures that had been wrongly grouped together in earlier analyses (an example is the sphere of possibilities that had been subsumed under the term ‘diminution’), thereby celebrating a newly revealed diversity of compositional procedures that had not been sufficiently appreciated previously.

Friedrich Ludwig, who coined the term in the early twentieth century, pursued a more general goal: to write a synthetic account of a period of music history. The discovery of the Ivrea codex (Iv) in 1921, which added a number of new motets to the repertory, allowed Ludwig's student Heinrich Besseler to flesh out a detailed narrative. For Besseler, the style of motet pioneered by Philippe de Vitry was an innovation that not only swept away the enormous diversity of late thirteenth-century motet types in France, but also, in its essentials, remained dominant for well over one hundred years, from c. 1316 up to the late motets of Guillaume Du Fay in the 1440s. This broader narrative recedes in Bent's sharpened critical perspective, despite the probability that Philippe de Vitry would have recognized Du Fay's Nuper rosarum flores as a motet. In my revised account, Vitry still figures as the key player, though the point of departure for this episode in music history depends more on literary factors than musical ones.

The following survey distinguishes three types of music – plainchant, vernacular song, and polyphony – each with a very different reception history. Plainchant enjoyed an active and constantly evolving reception even in the Middle Ages; its modern reception history dates from the efforts, beginning in the early nineteenth century, to restore the medieval shape of the chant, a project that would bear fruit in the early twentieth century. New interest in vernacular song came in the wake of philological and historical research into European languages strongly under way by the eighteenth century. The unaccompanied melodies, free from any religious association, were subject to a variety of adaptations, often tinged by nationalism and ideology. Medieval polyphony was completely lost until isolated fragments came to light in the late eighteenth century, and it was well into the twentieth century before its outlines became clear.

Most medieval music was improvised, and so is lost or only dimly discernible through performance directions in music theory treatises. Works transmitted in musical notations required an active generation-to-generation updating to remain current. Liturgical chant – a repertory not as stable as we might think – was retranslated, sometimes undergoing recomposition. Notations for secular monophony and polyphony tended to fall out of use, since each generation was sufficiently occupied with the cultivation of its own new music. By the time we reach the point when scholars took a modicum of interest in the remnants of medieval music – the mid eighteenth century – no one could read the sources any longer. The problem was particularly acute for polyphony, usually notated in separate parts.