I have a Flying Fish recording of a Klezmer band called 'Brave New World' The lyrics are included with the notes. Some of the lyrics are recent compositions by band members Michael Alpert & Alan Bern.

I had heard that 'those were the days' was originally in Yiddish. the DT identifies it as Russian. Does anyone have further details? I'm off to Jacob's Link to see if they have Yiddish words for Dona Dona; only the English is in the DT.