Marchetto of Padua’s Theory of Modal Ranges

Marchetto of Padua’s formulation of modal ranges in the Lucidarium (1317-18) ranks among his most important innovations as a music theorist. Like earlier writers, Marchetto distinguished between melodies (cantus) that, relative to their final tones (finales), ranged relatively high (tonus authenticus: authentic mode) and low (tonus plagalis or subiugalis: plagal mode). Unlike previous theorists, Marchetto also allowed for the possibility that a melody’s range might be ‘mixed’ (mixtus), i.e., by virtue of comprising substantial parts of both a high-ranging authentic mode and its low-ranging plagal counterpart. Moreover, within the authentic and plagal categories, Marchetto defined ranges he termed ‘perfect’ (perfectus: lit. ‘complete’), ‘imperfect’ (imperfectus: relatively narrow), and ‘pluperfect’ (plusquamperfectus: relatively wide-ranging). Also, Marchetto contrived a way to specify whether an individual melody with a very narrow range (e.g., spanning a sixth or less) should be considered authentic or plagal.