Have any dopers ever been responsible for concert security? How do you control boisterous crowds?

Per this threadI’m wondering about the mechanics of controlling really boisterous crowds. If a performers are allowing the fans to come close up how do you control stuff like flying bottles etc. without encapsulating the performers?

I worked the stage crew at the local arts center/theatre for four years.

Numbers.

Literally have enough muscle in the front to stand shoulder to shoulder - the performer should be on a stage raised above shoulder level.

Usually just having the stage raised is enough to keep the mobs off the stage so that you don’t need the line of muscle and a few heavys on the wings can run out and throw and climbers back into the pit.

If the audience starts throwing bottles, take the talent off the stage. If you can’t control the crowd, you shut down the show.

I was at a Green Day concert in Boston some years ago, at the Bandshell (forget the name now), where the crowd wen through all those stages in well under a minute once the show started.