Gregorian modality - A language for what message? a study of Gregorian modality by Jacques VIRET:
This book, intended for a wide audience of musicians and amateurs, provides an accessible and precise, lively and complete presentation of Gregorian modality. It approaches the latter from a primarily musical angle, without ignoring medieval treatises, and makes the results of a largely original research available to the non-specialist.
The approach adopted sheds light on the essential procedures of Gregorian composition: organisation of intervales, ornamental and other formulae, structuring of the phrase based on verbal accents, etc...
The author also develops a symbolic and esoteric explanation of the eight modes, a hypothesis that may help to elucidate the initiatory significance of Gregorian melody, as with all truly sacred art.
The author: Jacques Viret, Doctor of Letters, is Professor of Musicology at the University of Strasbourg II.