ABSTRACT
Research during the last forty or so years on the eight-mode system in both East and West has very properly focused on the documentary evidence. Outstanding contributions have included Michel Huglo's volume Les tonaires, Terence Bailey's The Intonation Formulas of Western Chant, and, much more recently, Peter Jeffery's magisterial survey 'The Earliest Oktoechoi'. As a consequence of this emphasis, there has been a parallel and ongoing search for simpler forms of modality, or tonal organization however it may be named, not only in the non-Gregorian repertories but also in the earlier stages of the Gregorian repertory itself. The simplistic assertion that Gregorian chant 'has' modes while others do not clearly contradicts the view that the modes were imposed on a Gregorian repertory not designed for them. One could ascribe such resemblances to 'Gregorian influence', but it is then difficult to account for the musical differences between the various versions.
