Today, few people have heard of the Altamont Free Concert, which took place on 6 December 1969. It was supposed to be the “Woodstock of the West” – a gathering of Hippies, drop-outs and music lovers from California and beyond.

Instead, it turned into a bleak, violent and deadly event, which was later dubbed the end of the Hippie era. Meredith Hunter, a young festival attendee, was killed by several Hell’s Angels, who had been hired to provide security during the event. There were reports of rapes and other violent episodes.

The Altamont Free Concert plays a minor role in my new novel, This Wild, Wild Country. It is the reason my band of Hippies abandons California and heads towards New Mexico, where they hope to rebound from the experience and renew their ideals.

The US Library of Congress has just released some new footage from the festival, showing 60s rock legends such as the Rolling Stones, Carlos Santana and Grace Slick. The footage does not throw any new lights on the events of that night, but it shows the stark contrasts that defined the – and perhaps contributed to – the slow decline of the Hippie movement.

The era created some incredible talent and revolutionised so many aspects of society, but it was also marred by chaos, conflict and fragmentation. The Hippies threw the rulebook out of the window. But then, where do you go from there?