Hundreds of years ago there was no such thing as freedom of speech in England. People who spoke out against the king or others in power were likely to be imprisoned and tortured in the stocks or killed.
But sometimes underground movements managed to communicate and spread their protesting ideas to others without getting caught by using a sort of code. Lots of them couldn't read and write and written things could be discovered and used against them. Of course telephones hadn't been invented yet so those people would wander through the street markets calling out messages only others on their side could decipher.
Years ago I read a book called The Real Personages of Mother Goose by Katherine Elwes Thomas. That book, which was published back in 1930, suggests many nursery rhymes were originally hidden political statements. For example Humpty Dumpty and Rock-a-Bye Baby might have been about overthrowing kings.
Common people often sang in the streets for the purpose of collecting coins for their music, but not everyone could sing or had an attractive voice. For that reason I wouldn't be surprised if some of those political rhymes were actually performed there like modern rap music.
Even if my guess isn't correct, it's fun to try rapping out some of those rhymes.
A more recent book, Pop Goes the Weasel; The Secret Meanings of Nursery Rhymes by Albert Jack, disagrees with Ms Thomas about the history of some specific rhymes, but agrees with her basic premise that some were originally political statements.
And, since I have a creative imagination, I enjoy thinking about rappers on the streets of England sharing news about their causes.