People of my vintage remember playing musical chairs at birthday parties, back before the days when money was so plentiful that it seemed to be important to impress the neighbours by hiring clowns and musicians or renting bouncy castles to entertain five-year-olds.
For those of you who did not have the pleasure of being pushed off of a chair by some mean kid who had fifty pounds on you, the idea was that music would be played while the children would circle a number of chairs that was always one fewer than the number of kids marching around them.