With very few exceptions, all vocal performances heard during the movie were original recordings of the 1930's group. The old material was de-noised and digitally enhanced.
In this film, Heino Ferch and Ulrich Noethen play Jews who are persecuted by the Nazi Regime. In A Queda! As Últimas Horas de Hitler (2004), Ferch played Albert Speer and Noethen played Reichsführer-SS Heinrich Himmler.
Ben Becker and Meret Becker, who play lovers here, are brother and sister in real life. Otto Sander (1941-2013), who plays Bruno Levy, was the Becker siblings' real-life stepfather.
As correctly shown in the movie every member of the Comedian Harmonists had to pay penalty when coming too late. One minute being too late costed indeed 3 Reichsmark, 5 minute too late was 5 Reichsmarks. And as shown in the movie, Erwin Bootz was the most unpunctual member.
One of Bill Clinton's favorite films.