The song "Zu Asche, Zu Staub" (to Ashes to Dust) of German TV series Babylon Berlin had its own success when the 16-part series aired on public television late last year. As filming for the next installment of the beloved 1920s series continues, Louise Gorman went behind the scenes in Berlin to speak to one of the composers of the unofficial theme song, to find out what all the hype is about.