Why does napoleon change the farm song?

Napoleon changes the farm song in George Orwell's "Animal Farm" to manipulate the animals and consolidate his power. By altering the song, he aims to erase the revolutionary ideals of unity and freedom, replacing them with Propaganda that glorifies his leadership and the regime's achievements. This shift helps to control the narrative, ensuring that the animals remain loyal and docile, ultimately serving Napoleon's interests rather than the original principles of the revolution.