Hi, Genie - Yiddish is properly written with Hebrew characters, but transliterations are common. I've noticed that Germans transliterate Yiddish differently from the way English speakers do it.
I think the song was originally English, with a few German phrases sung with an Americanized Yiddish pronunciation, but I can't tell for sure when I'm half a world away from my library. Interesting song, though.
Gargoyle, be nice.
-Joe Offer-