Previous searches: police at music festivals, police at rock against racism, police presence at music festivals.
Setting: London, 1976-77
Question: I'm wondering how many police might show up at three music festivals that occur in my novel. They occur in 1976 and 1977. At the first festival, it's very new bands, just known in London, and an audience of about 20,000. The second one has a crowd of 45,000, and the bands are now known throughout England. The third one has 75,000, and the bands are now just beginning to be known in France, Germany, and NYC. The bands are very rebellious punk bands, so there's a very deep suspicion and dislike of them in England. Also, the second festival has a theme of anti-racism, anti-National Front, and anti-Nazis.
I hope this is enough info. Thanks!