Tonary

A tonary is a liturgical book in the Western Christian Church containing various chant incipits which is organized according to the eight psalm tones of Gregorian chant. It may include antiphons and responsories from the Mass and Offices. Although they can be standalone works, they were frequently used as an appendix to other liturgical books, like antiphonaries, graduals, tropers, prosers, but also included in collections of musical treatises.

Function and form

Tonaries were particularly 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.