"I am a Camera" is the original play,
which was later adapted as the musical version of "Cabaret".
So wrote Christopher Isherwood in "A Berlin Diary - Autumn 1930", part of the book "Goodbye to Berlin", which in turn inspired both the Broadway play "Cabaret" and movie of the same name. They are a remarkable portrait of Berlin and wider Germany, a society in decay, in the final days of the Weimar Republic, just before the Nazis took over.
"Goodbye to Berlin" is as much a historical record as it is a personal record of Isherwood's 1929–1932 sojourn in Berlin on the eve of Adolf Hitler's ascension, although he later denounced his own writing, stating that 1930s Berlin had been "a real city in which human beings were suffering the miseries of political violence and near-starvation. The 'wickedness' of Berlin's night-life was of the most pitiful kind; the kisses and embraces, as always, had price-tags attached to them ... As for the 'monsters', they were quite ordinary human beings prosaically engaged in getting their living through illegal methods. The only genuine monster was the young foreigner who passed gaily through these scenes of desolation, misinterpreting them to suit his childish fantasy."
It's all there in the movie "Cabaret". To me, the most powerful scene in that movie is the above clip of the song "Tomorrow Belongs to Me", a nostalgic German folk song which develops into an intimidating military march as the instrumentation changes, more singers add their voices, and the boy's Hitler Youth uniform is revealed as he sings and salutes.
Before you are offended, note that the song was written and composed by two Jewish musicians, John Kander and Fred Ebb, as a warning to the rise of Nazism, and only later adopted as an alt-right political anthem.
