Our fifth form (O Level equivalent) Maths teacher in NZ said his very lower fourth class insisted on singing Pink Floyd's Another Brick In the Wall Part II at the start of each class (We don't need no education). He let them because that meant they would subsequently knuckle down.
He was a cool dude, large man, Commonwealth weight lifter. Once came across a woman who had got her Morris minor in a ditch. He lifted it out for her. Legs like tree trunks.