There is a musician and actor named
Conrad Janis. I looked it up, and that was the surname he was born with, not an assumed name. Because I was aware of this as his surname, I've occasionally looked to see if there is anyone with the surname
Janis in the phone book and I've found a few. Here's a page about the
Janis surname:
http://www.geni.com/surnames/janis
Not a very common surname, at least in the U.S, but a surname.