A crowd of overwhelmingly white young adults move in unison to the saccharine beats of Fred Again, a descendant of the Earl of Dundonald and the son of a barrister within the King’s Counsel. The tracks, although fun and well-performed, bandy somewhere between radio-friendly dance sludge and trendy beatmaking.

The setting is Glastonbury, the UK’s closest relative to the ‘free festival’ in which hippies danced to the iridescent spiralling synths of Hawkwind’s British Tribal Music in the shadows of Stonehenge. This contemporary evolution, though it tries hard to stay grounded in a feeling of freedom, finds itself caught in a pincer between corporate interests and the incredibly top-heavy economy of a rapidly deflating music industry.

Further back, even further than the free festival, towards the beginning of this amorphous tapestry of connections, comes the thumping beat of a soundsystem ensconced in a house, the sound reaches out into the air of the 1970s. Inside, as sociologist Ken Pryce put it, is something that most of the nodes of this tapestry have in common, a “dense, teaming, sweaty mass of humanity”.

This particular thread, ending with an artist like Fred Again, thrives. He makes music sickly sweet enough to appeal to a large swathe of tastes, Glastonbury is a descendant of hippiedom, but is granted space and corporate sponsorship in the new world through the foundations set in place by a bland Blairite vision of the “creative industries”.

There are threads elsewhere that have been frayed. They have been hounded, policed and in some cases, physically beaten into non-existence.

As mentioned, these threads are part of a larger tapestry. A network that allows people to throw off the shackles of the work-a-day world and life itself, a network where people of all ethnicities and backgrounds are able to express themselves. A network that encompasses immigration, political posturing, hippiedom, hardline policing, abandoned warehouses in towns lost to economic hardship, temporary autonomous zones, DIY festivals, radio stations and soundsystems. A network littered with drugs of all kinds. Some epiphanic and some fatal.

The network is near impossible to gauge in its entirety. But Party Lines, Ed Gillett’s new book on the evolution of dance music on the British Isles, allows passage to many parts of this incomprehensible mass, into the exciting blues dances and free festivals as well as the much less exciting politicking of Blairite Labour and the horrific actions of Thatcher’s Conservatives. Through Gillett’s hard work, readers can indeed catch glimpses of the unwieldy behemoth that is UK dance music. It is a book rich with information, anecdotes and analysis. Perhaps most crucially of all, it reifies those whose legacy was somewhat obscured bymore whitewashed tellings of UK dance history.

Party Lines makes it very clear that dance music is something that had to be fought for. We can see a targeted response from police in its initial emergence through soundsystem culture imported from Jamaica. Rampant overpolicing of clubs and black communities enabled the enforcement of prejudicious rules that had only recently been overturned, but were still favoured by authority. Though with less racialised malice, this was also the case when the hippie movement took this sense of DIY good times to rolling fields and prehistoric monoliths, as well as when it fed through into the halcyonic rave scene.

Gillett’s research also reveals how decentralised UK dance history is, bucking the assumption some may have that nothing much happened outside of London and a handful of other cities. Nottingham’s DiY collective and Cambridge-based Tonka Crew rocking up and joining forces with the travellers (a partnership described as an “unholy alliance” by West Mercia police) at the then-fairly unregulated Glastonbury to give rise to the ‘free party scene’ is a perfect example of this. The “unique and pivotal role” of Blackburn in providing the North of England with a place to dance before the police come is also given its deserved mention.

So too are the aspects of UK dance that are arguably without a physical location. The rise of stations such as Kiss gave DJs and tastemakers a chance to get themselves out there without hauling themselves down to some undisclosed location. Younger UK people may be surprised to read that what they now know as Kiss Radio was once a trailblazer of pirate radio. Currently owned by Bauer, the station’s story provides insight into the harvesting of culture that is rampant in the UK scene.

There are heroes along the way, from Pearl Alcock, whose clothes shop acted as "the only gay bar in Brixton" in the mid-1970s, to the pioneering Trinidadian Claudia Jones, who we have to thank for Notting Hill Carnival. From Philip Russell (or Wally Hope), who helped the free festival to its feet and puzzled a government increasingly hostile towards the counterculture by turning up in a Cypriot National Guard uniform to a prosecution hearing on their free love frolicking (Russell would pen a similarly flamboyant letter to a landowner which he scrawled with the now-famous icon of the smiley face), to the late Paul O’Grady, the act of the night at the Royal Vauxhall Tavern in 1987 when it was raided by police. After mistaking a police officer for a stripper, O’Grady suddenly realised the pub was filling with them. Only when his friends were being accosted he realised that the coppers had blue plastic gloves, as it was the zenith of scaremongering around AIDS. “Looks like we’ve got help with the washing up”, O’Grady’s legendary drag persona, Lily Savage said.

There are villains too. James Anderson, who had the role of chief constable of Greater Manchester Police from 1976 to 1991. He said that addicts, sex workers and all those associated were “swirling around in a human cesspit of their own making”, in reference to AIDs. His weaponising of Victorian values would lead to an advocation of corporal punishment for anyone who strayed from a incredibly regressive value set.

Over time, the enemy morphs a little, from a general swathe of bigoted police forces to more enthusiastic but predatory creative industries that, in many cases, care little for the community and positivity that dance music creates and more for the monetary gain that can be squeezed from it. Cue the dismantling of raves in favour of a corporate-sponsored day festival, attracting sponsorships while pushing out the more grassroots aspects. And, as ever, those who buck this trend will always feel the might of a heavily policed country.

But, throughout Party Lines, we are reminded of the beautiful essence of UK dance music. Its power to liberate and bring people together. Its ability to draw out incredible creativity. Its incomparable strength as a political weapon, to galvanise and to challenge authority. The pull to conform and to consume is ever-present. But, as the Criminal Justice Act itself puts it, that “emission of a succession of repetitive beats” can provide people of all ages and ethnicities with a means by which to connect to the people around them and create cohesion.

Party Lines: Dance Music and the Making of Modern Britain is available now