For those who flocked to Altamont Raceway Park in northern California on December 6, 1969, there was plenty of danger – and for those near the stage, horror – to go around. Any rock fan schooled in the ’60s knows what happened: a contingent of Hells Angels serving as security for the festival administered beatings to fans and musicians alike and stabbed to death an 18-year-old man just yards from an oblivious Mick Jagger as he finished singing Under My Thumb.

The tragedy has been chronicled in several books and most memorably in the 1970 documentary Gimme Shelter. But Joel Selvin’s Altamont: The Rolling Stones, the Hells Angels and the Inside Story of Rock’s Darkest Day provides rich new details about the origins of the show and the quest by Jagger and the Stones to stage the free concert.

The book chronicles the motivations, naivety and chemicals that led to what’s been popularly seen as the nadir of the Woodstock generation. In fact, Selvin makes the case that Woodstock, staged just 3½ months before Altamont, laid the groundwork for the disaster.

The Stones had been out of the American limelight and had missed the free festival in upstate New York. Meanwhile, the Grateful Dead and Jefferson Airplane had ascended and were playing free festivals in their hometown of San Francisco, which, Selvin argues, had become the centre of the rock universe in late 1969.

Selvin’s account begins with the Dead’s manager Rock Scully travelling to London to share his drug-addled vision with Keith Richards for the Stones to play a free show in Golden Gate Park. The Stones had just played a similar show in London’s Hyde Park, one in which they had used the tame British chapter of the Hells Angels for show security without a hitch.

The author does a good job taking readers through the Stones’ first US tour in three years and the recording of Let It Bleed during that concert run. At the same time, he outlines how Jerry Garcia relished the idea of the Grateful Dead headlining a festival with Jefferson Airplane, only to have the Stones appear unannounced at the end.

Selvin makes the case that Garcia saw such an event as marrying Haight-Ashbury to the London rock scene, a transatlantic communal experience. (Upon arriving at Altamont for their gig, the Dead surveyed the mayhem and elected to leave.)

Nearly 50 years removed, it’s hard to comprehend the chaos that ensued in the preparation and staging of the show. Throughout the Stones’ tour, Jagger teased the public with talk of a free concert. Even after the show was announced, two potential sites fell through. With just 36 hours to go, the concert – a crowd of 100,000 was expected, although actual attendance was nearer 300,000 – was moved to Altamont.

Staging and sound towers were erected overnight as a crowd began gathering and setting fires for warmth. The stage was lashed together with twine and stood only 120cm tall, compared with the 4½m version at Woodstock that had served as a barricade against the mass of humanity. Instead, Selvin writes, a piece of string separated the crowd from the musicians.

Selvin, who has covered pop music since 1970 for the San Francisco Chronicle and written extensively about the ’60s music scene, conducted more than 100 interviews with musicians, Hells Angels members, police, stagehands and medical staff. That said, the book at times feels thinly sourced, as the author surrenders attribution in service of the narrative.

That narrative accelerates in the second section of the book, as Selvin details the ominous vibe that builds throughout the concert. The omnipresence of alcohol and psychedelics among the 300,000 attendees, the lack of bathrooms and medical facilities, and the Hells Angels, paid in US$500 worth of beer, made for a hellish mix. By the time Jefferson Airplane’s Marty Balin was knocked unconscious by an Angel during the band’s set, it’s clear that for those who were near the stage, and for those on it, it was essentially a hostage situation.

The last third of the book focuses on the aftermath, including the police investigation into the murder of Hunter and three other deaths: a drowning and two car-related fatalities. In addition, Selvin describes the reporting that went into a comprehensive account weeks after the killing from a new publication, Rolling Stone.

While it’s clear that no one truly was in charge, Selvin ultimately lays much of the blame for the tragedy on the Stones, citing the band’s greed, hubris and naivety.

Plenty of accounts have been written about the concert, and the moment of Hunter’s death was captured on film for posterity. But Altamont serves as a valuable document, cutting through the hallucinogenic haze of the times to provide greater understanding of an American tragedy.