Who is singing the song?

I've looked high and low and can't seem to find out who does the song at the beginning and end of the film. Here at IMDB they simply state "unknow" and at Wikipedia, it's not mentioned. Surprised that in 80 years no one has come up with anyone, not even possible candidates. I thought it was a well done version of the song. I generally don't care for most of '30s vocal music but this one seemed to transcend that.










You've done some bad things, sweetie.