Vocalist Katharina Rothe lives a "double life." The German-born performer studied music and theater at university, and then went on to become Katharina Rothe, Ph.D, working as a clinical psychologist, psychoanalyst and psychosocial researcher. Her passion for the stage has been ongoing, and her latest outing is Come to the Katberet!, playing this Saturday, October 1 at Don't Tell Mama. NLE: Your new show, Come to t…