Why do Napoleon and Squealer consistently emphasize ceremony?

In Animal Farm, Squealer and Napoleon introduce and promote a number of ceremonies. What is most striking about these ceremonies is that they are used to increase the power and prestige of both pigs, particularly Napoleon. Notice that orders are always issued through Squealer. Also, in chapter eight, Napoleon and Squealer ban the singing of "Beasts of England" and replace it with a poem written by Minimus. Moreover, in this same chapter, Napoleon is  given a special title, "Our Leader, Comrade Napoleon." All of these ceremonies and rituals, therefore, increase the power of the pigs, cementing their authority and destroying the principles of Animalism.
Ceremonies, therefore, have enabled the pigs to slowly transform the farm into their own dictatorship. This is why they emphasize ceremony so much: it is one of their sources of power, and they cannot have their social order disrupted.