A weighty document at over 600 pages, reading between the lines of John Masouri’s intro to Pressure Drop suggests he’d agree it could have been much longer. It’s an overview of reggae music as it evolved throughout the 1970s – at the decade’s inception, almost all reggae was recorded in Jamaica, on relative shoestring budgets, and was an understandably insular culture. By 1979 the genre had produced global stars, been subject to various sonic alterations based on technology and tastes, and scenes had sprung up worldwide, notably the UK.

The reggae industry exploded over 10 years, with musicians, studios and labels often working at prodigious rates. Masouri namechecks hundreds of records in Pressure Drop’s pages, and proves a genial guide – not one to dispute an album’s ‘classic’ status, as a rule, but also willing to concede that polished, chart-friendly reggae can be a blast too. If sacred cows are poked, it’s primarily in anecdotes about the business acumen of certain institutions – the late Lee Perry, as responsible as anyone in this book for opening new sonic frontiers, is painted as a deeply shady bastard whose infamous ‘craziness’ was at least partly a put-on to get people to leave him alone.

Masouri’s sourcing seems robust, with the author able to draw on several dozen of his own retrospective interviews: a reggae fan since his teens, and during the decade covered here often one of just a few white faces in London clubs, he began writing about it professionally in the late 80s. Nevertheless, it’s not clear if Pressure Drop had a dedicated copy editor: the amount of clunky grammar and punctuation makes me suspect not, and that’s without mentioning goofs like describing Don Letts as a “reactionary” when introducing an anecdote indicating quite the opposite.

And yet this is a book whose writing is still worthy of drawing you in and bundling you along the timeline. Each year is given its own chapter, and Masouri reels off events as they happened day by day, or as close as historical records allow. The close-knit nature of the reggae scene at the time – most participants knowing each other, or knowing someone who did – is reflected in thematic segues between paragraphs which help to uphold momentum.

By the time reggae had been well and truly imported to Britain, with bands and soundsystems forming in larger and more diverse cities, punk was just around the corner, with icons like John Lydon and Joe Strummer trumpeting their fandom. The Specials and other 2 Tone acts would make their appreciation more sonically evident, impinging on British youth culture as the decade fades out; Masouri writes warmly of these developments while noting that they replaced actual reggae and dub in wider – whiter – critical affection. He doesn’t shy away from the social issues endemic to reggae culture, either, with Jamaica’s decade-long descent into a grim hive of guns, poverty and corruption regularly spiking the recollections of this brilliant, epochal music.