Crowd control

“After World War I, Hanussen performed a mind reading and hypnosis act at La Scala in Berlin that catapulted him to stardom. At his height, he enjoyed the company of Germany's military and business elite, also becoming close with members of the SA. It is claimed he was a supporter of the Nazis despite his Jewish ancestry, which was an open secret. […] Stories abound of meetings between Hanussen and Hitler, including an encounter shortly before the election of November 1932, during which Hanussen taught Hitler his crowd control techniques of using gestures and dramatic pauses”
Source: https://en.wikipedia.org/wiki/Erik_Jan_Hanussen