In 1923 Hitler adored American football marches and college songs. The 'Sieg Heil!' used in all political rallies is a direct copy of the technique used by American football cheerleaders. American college type of music was used to excite the German masses who had been used to very dry-as-dust political lectures.
document recently declassified by the CIA - a psychological profile of Hitler assembled in 1942 by one of the CIA's forerunners, the Office for Strategic Services.