Tonary - Function and Form

Function and Form

Tonaries were particular important as part of the written transmission of plainchant, although they already changed the oral chant transmission of Frankish cantors entirely before musical notation was used systematically in fully notated chant books. Since the Carolingian reform the ordering according to the Octoechos assisted the memorization of chant. The exact order was related to the elements of the "tetrachord of the finales" (D—E—F—G) which were called "Protus, Deuterus, Tritus", and "Tetrardus". Each of them served as the finalis of two toni—the "authentic" (ascending into the higher octave) and the "plagal" one (descending into the lower fourth). The eight tones were ordered in these pairs: "Autentus protus, Plagi Proti, Autentus Deuterus" etc. Since Hucbald of Saint-Amand the eight tones were simply numbered according to this order: Tonus I-VIII. Aquitanian cantors usually used both names for each section.

The earliest tonaries, written during the 8th and the 9th centuries, were very short and simple without any visible reference to psalmody, the most tonaries which survived until now, can be dated back to the 11th and 12th centuries, some were still written during the following centuries, especially in Germany. The treatise form usually served as a bridge between the Octoechos theory and the daily practice of prayer: memorizing and performing the liturgy as chant and reciting the psalms. This can be studied at a 10th-century treatise called Commemoratio brevis de tonis et psalmis modulandis, which used the Dasia-signs of the Musica enchiriadis treatise (9th century) in order to transcribe the melodic endings or terminations of psalmody. 11th-century theorists like Guido of Arezzo (Regulae rhythmicae) or Hermann of Reichenau (Musica) refused the Dasia tone system, because it displayed tetraphonic tone system and not the systema teleion (corresponding to the white keys of the keyboard) which had all the pitches needed for the "melos of the echoi" (ex sonorum copulatione in "Musica enchiriadis", emmelis sonorum in the compilation "alia musica"). Nevertheless the first example of the eighth chapter in Musica enchiriadis, called "Quomodo ex quatuor Sonorum vi omnes toni producantur", already used the fifth of the Protus (D-a) for an illustration, how alleluia melodies are developed by the use of the intonation formula for the "Autentus protus".