Mode and change of mode in the 13th-century motet

Abstract

The many different versions in which motets were notated in various manuscripts from the 13th century testify to the great flexibility of this genre. The present paper pursues those few clues in practical and theoretical sources which indicate that the rhythmic mode itself was often subject to change within a particular group of motets. Evidence of this practice is found in the early group of the manuscripts and then, again, in tlie later, more liturgically oriented sources, including Las Huelgas. In the former, first and second modes could be interchanged to correspond to Latin or French texts, respectively, and in later times the notated combination of third and fifth modes, now considered out of date, could simply be performed as sixth and second modes. In both cases the change of mode appears to represent a quasi-improvisatory practice which could be performed without altering the written version, i.e. it was probably much more common than the sources themselves indicate.