The episode title, "Mutterseelenallein ", roughly translates to "The mother of all loneliness".
Despite Pieter assertion to the contrary, there is no evidence that dairy products, especially milk, increase phlegm or the viscosity of phlegm, which would impact upon a singer's performance.
One of the Judges is named Hans Schröder. who is nick-named Edward Scissor-hans (derived from the film, Edward Scissorhands (1990)). Incidentally, Hans last name Schröder, is an occupational name for a tailor or cutter of cloth, from the Middle Low German (Low German refers to the region of Northern Germany especially near the North and Baltic Sea) schroden or schraden, meaning "to cut." Moreover, there was a German Chancellor (Head of Government) named Gerhard Schröder.
Bumper was paying homage to Charles Chaplin when he did the "fork dance" with prawns. The original performance was done with dinner rolls.
The Berlin Wall was constructed in 1961, to keep the peoples of East Berlin, which was part of East Germany and allied with the Communist Soviet Union, from fleeing to the freedom and safety of West Berlin. It was brought down in November 9, 1989, after the fall of Communism.