Khrushchev's memoirs.
In his memoirs Nikita Khrushchev told about Stalin's management style. Stalin drank a lot, a very lot, and would start working in the evening with his staff. Around 3:00 AM Old Joe would be pretty drunk and the meetings could get lively. And Joe could get iracible.
Several times he made Khrushchev get out in front of everyone and do a version of that dance, including the squat-kick which looks so utterly painful. Nikita says it was extremely difficult for his body style and condition, but he was afraid not to try.
Actually, Khrushchev was a bit bitter about it.
Arf