Beyond the standard and familiar theoretical instruction materials on notation and mensuration, on mode and hexachord, and on the rules of two-part counterpoint, information and insight about the techniques of musical composition in the later Middle Ages are hard to come by. From a modern vantage point, medieval music theory leaves many of the questions most interesting to us unanswered. And for our part, too, analysts of chansons and motets have yet to agree on many basic notions about how this music works, and therefore what is most necessary to talk about. It is symptomatic of this state of affairs that articles discussing analytical approaches to early music, even those addressed to specialists, do not start out in medias res but rather must begin with first principles, and that current textbooks ignore or skimp on all but the most superficial aspects of musical style. We need to establish for all genres the paradigms or fundamental givens, the constraints understood at the outset, the range of choices available to the composer.

The idea of reconstructing fragmentary polyphony has not really found a niche in mid-fifteenth-century studies. Whilst editors of Baroque music have become quite used to reconstructing string parts to ‘arie con tre violini’ in skeletal opera sources, and whilst sixteenth-century specialists have occasionally been brave enough to recompose the contents of a lost partbook, this sort of treatment has rarely been applied to fragmentary works of the Dufay and Ockeghem periods. There seem to be two reasons for this. Firstly, since many of the essentials of mid-fifteenth-century style are not based on imitative techniques or the realization of simple chord progressions, the random nature of what an incomplete piece of the period might contain can make plausible reconstruction very difficult. Even the most predictable-looking of complete mid-fifteenth-century works often have surprising rhythmic turns or unexpected progressions, simply because variety was an expected and prized aspect of the mastery of sophisticated polyphony as it was then understood. Secondly, even if an editor achieves what he considers to be a satisfactory reconstruction of such a work, there are few cases of such reconstructions in which there is an overall conjecture rate of less than 20 per cent. Nevertheless, there are exceptions to all generalizations and on the present occasion I believe I have found a movement from a fragmentary cyclic Mass that can be reconstructed with comparatively little conjectural material: the Gloria from the Missa Salve Regina in Munich 3154. This article describes how I became interested in the cycle and suggests how the missing material in its Gloria can be effectively realized.

Munich, Bayerische Staatsbibliothek, Mus. MS 3154 folios 47v–48r preserves the unique text of Busnois' motet In hydraulis, reproduced by D. Plamenac in Die Musik in Geschichte und Gegenwart IX Tafel 116.

Anyone who pays attention to the popular news media will have read or heard a lot lately about the rapidly expanding international network of computer networks known as the Internet. Though the Internet was originally developed by the universities to support international research cooperation and the exchange of scholarly information, the hardware and software have become so cheap and easily available that many commercial firms, non-educational organizations and individuals are now connected to the Internet also. The most explosive growth has been in the multimedia portion of the Internet, known as the World Wide Web, which is able to transmit computerized image, video and sound files as well as text. The lack of any central authority that can regulate or moderate the content of Internet communications has forced governments and citizens to become increasingly embroiled in issues of free speech, fair trade and community responsibility – yet despite the empty chatter, political grandstanding, sales hype and pornography, the Internet remains an unparalleled and unprecedented medium of valuable information, much of which would otherwise be unavailable to many, or available only with extensive travel, inconvenience or expense. The quantity of such information increases daily, and it includes much that is helpful to serious students of medieval music and chant.