All I know about Arkadi is that he married Charlie's sister Ilse, probably in Berlin.
How they met, where they lived, how they lived... and how they died, all of that is unknown. Their names do not appear in the Yad Vashem pages of testimony, a fact I find very strange. Charlie must have been searching for them after the war, and I do not believe he did not submit the names of his family to YVS already during the 1950s.
But still - Arkadi is the only one from the whole Jordan family in Poland whose fate is at least a little bit traceable. There is no data on Ilse, nor Hertha, the mother.
I know by now that Arkadi played with his own orchestra in big hotels throughout Poland and Germany, including the famous "Patria", a hotel owned by Jan Kiepura. I also know that after leaving Berlin in 1933 he was an arranger for the Warsaw radio, and also for Odeon Records in Warsaw. It seems the family lived in Lodz for a while. There are small pieces of information about Flato performing in the Warsaw ghetto, usually with Arthur Gold, the later kapellmeister of Treblinka. After the first big wave of deportations, there are several testimonies about Flato, a master violinist, surviving in a small labor camp - but that Flato seems to have been a young fellow. I have no idea how old Arkadi was, but surely he was not that young. Or was he?
It is not known to me whether Charlie tried to get his family out of Poland at all, and if so, then when - or how. All we seem to know is that they perished. And that the whirlwind of WWII obliterated almost all material records of their existence.
Almost all - but not all. Some of the recordings made by Arkadi Flato are still popular in Poland today - you can listen to them here:
http://www.youtube.com/watch?v=OuhDqmbKkTkhttp://www.youtube.com/watch?v=rJQUsC34ICM
http://www.youtube.com/watch?v=HkPV2wJwgYgAnd here is a Warsaw Ghetto poster advertising an afternoon concert of Arkadi Flato - playing with the hero of the film "The Pianist", W. Szpilman:

If only I knew where one may find the unused affidavits for the Polish, Russian or German Immigration quota. (In case Charlie ever filed an affidavit for his family, of course). If only I knew at least a place and date of birth of someone.