Rowan et al-

Is there a short answer to the roots of "the German cabaret scene of the 20s and 30s"? Is it early jazz, Balkan based, or what? There doesn't seem to be anything equivalent in American popular music or Broadway show tunes during the late 1920's or early 1930's. What planet did Weill and Eisler come from?

Cheerily,
Charley Noble