INDIVIDUAL OR PAIRED polyphonic mass movements from the medieval and Renaissance periods rarely achieve anything like the prominence commonly enjoyed by mass cycles, songs, or motets. A notable exception is a three-voice Kyrie setting believed to date from the 1430s that survives with an attribution to Du Fay in one of its sources (Tr92). This setting was first published in 1932, as part of a selection by Heinrich Besseler of twelve of the composer's sacred and secular works, where it was included as the only example of a movement from the ordinary of the mass. In 1962 it was published as part of Besseler's edition of the Du Fay opera omnia, and, perhaps by no coincidence, was commercially recorded the following year. The work had been used to illustrate the entry on ‘Cambrai’ in the first edition of Die Musik in Geschichte und Gegenwart (Illus. 1), and was already familiar to generations of students from Apel's manual on notation, where extracts from one of its sources are reproduced. Several writers singled it out for special mention. In 1975, the year following the quincentenary of Du Fay's death, Craig Monson published a substantial study of the piece that decisively rejected the composer's authorship. Since then it has been the object of little more than passing attention in the literature.

Most students transcribing this Kyrie will have been struck by its intricate rhythms, as well as by some of its (to them) more unusual notational features, such as the ‘displaced’ coloration group near the opening of the contratenor, or the notation of the Christe in ₵ rather than C (see Ex. 1). Many, having familiarized themselves with the music – perhaps with the help of Konrad Ruhland and the Capella Antiqua of Munich's fine recording – will have been captivated by its extraordinarily subtle beauty. But few, if any, prior to Monson will have had even the slightest doubt as to the attribution's authenticity. And there is no particular reason why they should have done, given that until the 1970s Du Fay's authorship of the work seems to have been accepted unquestioningly, and without exception, by scholars and performers alike.