We would have daily / regular assembly of the whole school (usually youngest at front) where the headmaster would give some admin and some moral lesson. Sometimes there were more interesting things happening. But I suspect the British tendency to queue might come from there.
Just wondering :-)
After moving to Canada:
In junior high school, we'd get to school at 9AM and class would start by 9:15AM after the national anthem and daily announcements.
High school: Got to school by 7:50AM, music played on the PA system until 8AM, after which the Pirates of the Caribbean theme would start to play to urge us to get to class faster. Then the national anthem, daily announcements, and classes would start by 8:20AM.