They were the brightest and the darkest years in the history of the musical metropolis of Berlin: From the founding years via the roaring twenties to the Third Reich. And right in the middle and setting the tone: the composers Walter and Willi Kollo. Willi Kollo's notes on the musical career of his father, one of the masters of the Berlin operetta, and on his own work as an author, composer, revue performer and director are a treasure of German cultural history that has not been raised yet. With...