Yiddish: If the girl can't dance, she says the musicians can't play.

SOURCE: Bernstein, Jüdische Sprichwörter und Redensarten.
The Yiddish word klezmer refers to the musicians, not to the music.

אַז דאָס מיידל קען ניט טאַנצן, זאָגט זי אַז די כּלי–זמר קענען ניט שפּילן.

Az dos meydl ken nit tantsn, zogt zi az di klezmer kenen nit shpiln.

If a girl can't dance, she says the musicians can't play.