Law and Red tape on public gatherings where music is played etc

Hello,

I'm looking for some clarification with regards to laws and red tape relating to public gatherings, outdoor parties and raves etc. i am an great advocate for the rights of persons to gather in a public outdoor place, and party/play music etc and get very angry about councils and police who feel they have the right to spoil peoples fun without seemingly much regard for the law which i have heard numerous versions and interpretations of over the years.

More specifically I was under the impression a law was brought in in the thatcher years relating to a limit on how many people could gather in one place and specifically mentioning "repetative beats" the implication being that this was somehow illegal. Is this true or rumour? And I have also heard contradictory reports regarding whether this law was repealed.

Additionally, I would like to know what powers to police have to shut down such a gathering or to confiscate equipment on whatever grounds whether it be noise "nuisance"/disturbance licensing etc - The specific wording of these laws would be helpful aswell us under what circumstances they could be or would be likely to be practically applied. i.e in what circumstances would a court order be required?

But back on the more general theme, i guess the crux of what i'm getting at is, at what point and under what circumstances/criteria exactly does a gathering between people who may wish to play music become unlawful or illegal? - And also how does the law differ exactly depending on whether it is held on public or private land, or perhaps on land owned by another body such as the national trust etc

How can a spontaneous, unplanned street party for a royal wedding be supposedly legal (assuming it is not blocking traffic) as the prime minister himself said when he seemed to criticise of local authorities for mis-leading people in to believing they needed to make all sorts of legal applications and seek various permissions, music licences insurance etc etc. If this is the case when why should it be any different simply because of group on individuals happen to have a preference for a different kind of music which happens to feature repetative beats? - I suspect there may be a lot of interpretation of the law involved here, but some cold legal facts and perhaps legal precedents where interpretation is the issue would be of great assistance.

Just to clarify i am more concerned with what legal powers and laws are enforceable by police, on site, while an event is in progress rather than the kind of issues that may be dealt with by courts or councils after or prior to an event, so more emphasis on that would be helpful for anyone looking to give a shorter answer, although the more information that anyone wishes to provide the better and more grateful i would be. Or perhaps these different areas are far more intertwined then i perhaps realised?

Regards