This disc elicited a good deal of musicological huffing and puffing, some of it very knowledgeable, some rather less so but still perceptive, and opinions remain sharply divided. Some of the arguments for the supposed authenticity, or lack of it, underlying the performance choices made here are plausible, others highly conjectural. As it is very difficult to know to what degree performance of this music could feasibly have been influenced by Corsican or Moorish singing, in the end one must simply decide if it sounds artistically appropriate and aesthetically pleasing sung this way.
My instinct is that there is a gross disjuncture between the raw notation and the vocal style adopted. The braying, groaning, sliding and warbling melismata which characterise the interpretation here by the Ensemble Organum seem to me to be to odds with the slender flame-like intensity of the essentially spiritual thrust of what is, after all, a mass. It's all too fussy, too self-regarding and, actually, rather samey once one has got used to the idiom. I am not necessarily saying that only the hooty, choir-boy purity of a modern Oxbridge chapel choir will do, but their way is surely more incongruous. If I want to hear medieval liturgical polyphony sung in traditional Corsican style, I shall turn to the wonderful Barbara Furtuna Ensemble - and for Machaut in what I suspect is a mode closer to his intentions, I return to the bargain Naxos disc by the Oxford Camerata.