Hi:

I think I can verify the association of the Schnitzelbank song with the carnival season. I recently purchased an old framed black and white photograph showing a small band of (clown) performers with face
make-up,costumes and musical instruments, holding a sign in German with the words, "Schnitzelbank" written on it and the beginning verse of the Schnitzelbank song, plus small cartoon characters or vignettes on the sign. There is no date or other identifying markers on the photo to indicate time or place, but I feel very strongly that it dates to at least to the 1910's. I think this might even be Pennsylvania Dutch, and not German, because one of the clowns wears a bowler hat with s small metal badge with the word, "Police" on it.

                           AL