The "Plainsong Mass" of Reginaldus Liebert (ca. 1425): Some Practical Speculations on Speculative Practices

"The 'Plainsong Mass' of Reginaldus Liebert (ca. 1425): Some Practical Speculations on Speculative Practices." Although remaining little known, the three-voice mass cycle of the obscure Franco-Flemish composer Reginaldus Liebert is significant historically in that it comprises settings of all the Ordinary texts (excepting Ite missa est) as well as a full set of Marian Propers. As such, it represents the most comprehensive entity surviving from the late-medieval repertoire of liturgical polyphony. By virtue of its status as a unitary composition, the Liebert Mass affords a particularly valuable perspective on the interrelated issues of performance practice and tonal organization, both of which are inevitably affected by the modern interpreter's construal of the pitch sets implied by variable accidental signatures, the elaborated plainsongs present throughout as cantus firmi, and the invoking of both notated and unnotated pitch inflections. The results of this study lead the author to argue that the tenor voice is the key to tonal coherence throughout the cycle, the recognition of which allows for a systematic delivery of pitch content in the other voice parts.