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...