At first glance, genre is a hugely powerful concept in chant. Within the central liturgical repertory, each chant belongs to a genre – introit, responsory and so on – and there is rarely any controversy over which genre a chant belongs to. There are several obvious reasons for this. Firstly, many chant genres are easily and meaningfully defined by liturgical function. There is never any question about whether, for example, an introit functions rather like a gradual. An introit is sung during the procession into the church, not between the readings of the Mass and, as such, is clearly an introit. Jacobsson and Treitler refer to genre in this sense having ‘a neutral connotation, doing little more than identifying the divisions in a taxonomy’ and, indeed, it is completely straightforward to create a hierarchical taxonomy of many chant genres according to their liturgical function (see Figure 1 for a partial taxonomy).

As well as being clearly differentiated by liturgical function, some chant genres have internal musical structures which unify them as genres. Each of these families of chants is derived from a melodic type or formulaic system. This goes for the tracts and for many of the graduals, alleluias, responsories and antiphons. Further, chants are consistently given genre labels in the manuscript sources, right back to the unnotated Mass Proper manuscripts of the eighth and ninth centuries. The association of each chant with a particular liturgical genre was integral to the tradition. Genre is a strong concept in the study of chant because the genres identified by a taxonomic approach – according to the hierarchical division of the repertoire according to Mass and Office, Proper and Ordinary and so on – coincide with the genres one can identify according to melody type, and with those identified by medieval scribes.

However, there are several complicating factors. By categorising chants according to genre, one risks missing interesting textual or musical interplay between chants of different genres, such as the shared material on ‘leonem et draconem’ in the Quadragesima tract Qui habitat and the Quadragesima offertory Scapulis suis discussed on p. 91. Similarly, it is easy for a scholar to become so focused on the melodic language of a single formulaic genre that (s)he misses melodic strategies used across several genres at a deeper structural level than formula.