Hi from Paris,
I have been often in New York for my researches at :
Center for Jewish History https://www.cjh.org/
Yivo  https://www.yivo.org/
and I know they detain archives on Yiddish theater, in Europe and in America, specially New York.
Khavershaft
Bernard Flam
Archives & History at Medem Center - Arbeter Ring (Bund / Workmen Circle of France)