In the video description below we can read:
«...L’insegnante, Dimitrios Vatikiotis, è un Maestro diplomato in Grecia, ed è primo cantore presso la Cattedrale greco-ortodossa di San Giorgio dei Greci a Venezia.»
I have put the whole italian text in google translate, which gave me the following translation:
«The Santa Eufemia Institute offers a course in psaltica, or Byzantine singing, aimed at all those who are interested in knowing and practicing this thousand-year-old musical tradition, which is still practiced today in the majority of Orthodox churches throughout the world and in all languages. The teacher, Dimitrios Vatikiotis, is a Master graduated in Greece, and is first cantor at the Greek Orthodox Cathedral of San Giorgio dei Greci in Venice.»
You can contact the Greek-Orthodox Metropolis of Italy (Sacra Arcidiocesi Ortodossa) or you can search the name "Δημήτριος Βατικιώτης / Dimitrios Vatikiotis, first cantor at the Greek Orthodox Cathedral of San Giorgio dei Greci in Venice on the Internet" or similar requests. There is also an email address in the video:
segretaria.ito@gmail.com.
Please let us know the name of the choir.