I bought boxsett of two CD-s, Peres Portrait and Machaut's Messe de Notre Dame by Organum long ago, in 1997. Those years I was looking for and buying a CD of the Messe de Notre Dame without making up my mind. I found everything available in CD shops in London, but that was not so much. When I heard for the first time the Organum performance of this Mass I really near fell over. I already heard Deller, Oxford Camerata, Hilliards and Pro Musica Antiqua, but Organum offered something quiet different and exceptional to my ears. Meanwhile, I heard different opinions about it.
For example, our respected member of the intoclassics.net, Вадим Родионов, said this: "Своеобразное исполнение в восточном стиле, которое, в данном случае, совсем не сочетается с музыкой Г. де Машо." (http://intoclassics.net/news/2015-06-27-3810).
Also, at some musical blog I have followed in 1998 I heard two listeners commenting:
I. “It reminded me what medieval music was all about and why I do it. I'm not convinced that the interpretation has anything to do with historical performance -- it probably has more to do with Georgian polyphony -- but it has everything to do with the spirit of the music. It's not often that I would go to the trouble to write to the list just to rave about a recording, but in this case, I must say that if you haven't heard this recording, you must! It's not pretty, but it's stunning. Give it a listen".
II. “I'm not convinced that the interpretation has anything to do with historical performance -- it probably has more to do with Georgian polyphony”. How right! and maybe more with Corsican polyphony... (excuse-me, but I am Corsican and I know the subject, I know also Organum). “It's not pretty”. How right! they never knew how to sing but they obviously know how to sell! Conclusion: I go and buy it immediately because I am so curious.
Well, on contrary to all this, I still love very much their performance.