Choreographed spontaneity

[Luis Fok]

Used to describe the scene in [musicals] where people in the street know the words and tune to the song sung by any main character, and instantly know the dance routines including, but not limited to: jumping over [barrels], swinging girls in the hair and [juggling]. This is all despite being total strangers.

This is all supposed to be spontaneous, of course, but naturally - its actually choreographed