Chant scholars who attempt to deal with their subject in the pre-Carolingian period will sooner or later come up against the formidable oeuvre of Antoine Chavasse, the eminent Strasbourg scholar who dominates the field of Roman liturgical history from the sixth to the eighth centuries. A knowledge of the development of the church year is crucial to speculation on the chronology of early chant, and Chavasse has written extensively on every phase of the subject – on Lent especially, but also on Paschaltide, Advent, and the Sundays after Christmas and Pentecost. While he has not neglected the sanctorale, his emphasis has always been on the more demanding area of the temporale. There are other scholars who have contributed much to the field, but none could be considered even a close second in either the scope of their contribution or its influence: frequently one finds other liturgical scholars accepting without question some of Chavasse's most far-reaching conclusions as premises to their own work.

Among the ten celebrations of the Mass of St Basil in the Orthodox Church during the year are the conclusions to the three Vesper services immediately before the three major feasts of Christmas, Epiphany and Easter. Two of these Vesper services – those for Christmas Eve and the Eve of Epiphany – are of particular musical interest since they contain psalms with troparia or antiphons, for both of which the entire music can be transcribed from thirteenth-century manuscripts, so that these two services can be celebrated with what are, almost certainly, the oldest known complete examples of Byzantine psalm singing. From a recent paper of mine on these psalms, it can be gathered that they are examples of what is known as ‘responsorial psalmody’, the psalm itself being sung by a soloist, and the attached troparion by a choir of trained singers or psaltae. In both services they occur as punctuations of a series of readings, appearing in each case after the third and the sixth reading. On the Eve of Epiphany we should perhaps expect to find further psalms after the ninth and twelfth readings, since the series extends to thirteen readings in modern service books and to twelve in the early Middle Ages; yet no such psalms appear now or seem ever to have been sung at this point. And similarly, on Holy Saturday, when according to the ancient Jerusalem cursus twelve readings were given, to be extended in Constantinople to fifteen, no equivalents seem to have been performed at any point.

The two pieces introduced and briefly discussed in this article have so far remained unnoticed because of the manner of their notation. In each case pieces of two-voice polyphony were notated with the two voices separate, instead of in the score notation which has been usual since, roughly, the second half of the twelfth century. In the one case, the sequence Magnus deus in universa terra in a manuscript from Marchiennes of the fourteenth century, a second voice was added at the back of the book in which the usual melody had already been recorded. In the other case, the song Ad honorem regis summi in the so-called Codex Calixtinus, the two voices are notated successively, verse 1 of the text being given with the first voice, verse 2 with the second voice.

The critical study of medieval chant, which began in the mid-nineteenth century, is one of the oldest of the disciplines that coalesced into modern musicology. It is also one of the most international, for liturgical chant traditions represent the earliest preserved musical heritage of a great many different countries that are heirs to the medieval Latin and Byzantine worlds and their satellite cultures, ranging from Finland to Ethiopia, from Iceland all the way to southern India. In more recent times the knowledge of these traditions, particularly Gregorian and Byzantine chant, has spread to every continent as Western religious, musical, and educational traditions have been introduced throughout the world. Chant studies, therefore, are being pursued all over the globe, by hundreds of scholars writing in dozens of languages and utilizing countless different approaches – scholars who also desire the benefits of being in better contact with each other. It is to help keep track of these many independent scholarly efforts that the Liturgical Chant Bibliography is being published here, as the successor to the Liturgical Chant Newsletter. Future instalments will appear each year in the second issue of Plainsong & Medieval Music. All chant publications likely to be of interest to scholars are eligible for inclusion, provided (1) they have actually been published and (2) I have been able to see a copy, or have at least received complete bibliographical information (including author, title, publisher, date, page numbers).