Some years ago, I had to ask Greek friends to buy these CDs in the bookstores of the Orthodox church, today you can buy them directly online:
The webpage e-kere presents the publishing and research activity of the Research and Publication Centre (KERE), and of Manolis K. Hatziyakoumis.
Not as good as a living teacher, but very useful to understand the tradition. The founders of MMB would have abandoned certain extravagant obsessions about the past, if they could have listened to these recordings.
Whether in the English or in the Greek version, the page is very generous provided with music examples and I really recommend to visit it.
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