(Gregorian Studies) A series of scholarly studies on technical questions regarding the Gregorian art as well as that of chanted liturgical prayer in all of its various aspects--History, Liturgy, Canonic Rites, Philology, Paleography, Semiology, Rhythm, Modality, Esthetics, Polyphony, Accompaniment and Organ. Published at irregular intervals by the Monks of Solesmes. Usually in French, depending upon the native language of the author.