(idiom) a boiling cauldron of voices; describes the loud, noisy hubbub of a large crowd of people

A massive upsurge of public feeling, describing a situation where the masses are highly excited or indignant, like water boiling in a pot.

everything under heaven is boiling like a cauldron; used to describe a country in a state of chaos and social unrest

(idiom) popular grievances boil over; widespread public anger

Used to describe a scene of intense hustle and bustle with many people singing and instruments playing loudly; exuberant and noisy celebration.