Major sings "Beasts of England" and teaches it to the other animals for a few reasons. The song brings together the animals in a communal activity, singing, but the song also instills a message of revolution in those who sing. In many historical revolutions, songs served to simplify and spread revolutionary messages to the masses. Rather than sitting and teaching everyone theory, history, and philosophy that might underpin the revolution, songs are a way of uniting people through the act of singing and teaching them points that are easy to understand.
In Animal Farm, "Beasts of England" also connects the animals with an old history of animals who struggled and labored long ago. Major explains to the other animals that the song was "sung by the animals of long ago and... lost to memory for generations." The animals adopt it as a song symbolizing their freedom at first. They sing it after the Battle of Cowshed and they sing it to themselves after the Revolution.