“Oh, to capture just one drop of all the ecstasy that swept that afternoon,” keened David Bowie on Memory of a Free Festival from his second album. It’s a song that gives its name to Sam Knee’s evocative collection of unpublished photographs of the musical gatherings that flourished in the wake of the 1956-61 Beaulieu jazz festivals. Many were held in places – Richmond, Uxbridge, Sudbury – rarely celebrated as countercultural havens. In the early days, performers often appeared on bandstand-sized stages before modest crowds who look like contestants from University Challenge. Soon different tribes – among them hippies and Hells Angels – emerged. John Peel appears at the 1973 Reading festival next to a poster of a policeman: “Watch out! There’s a fuzz about.” Knee salutes underheralded anarchist organisers such as Bill “Ubi” Dwyer and Wally Hope. The real stars of his book, though, are the crowds – teenagers, dreamers, self-emancipators.

• Memory of a Free Festival by Sam Knee is published by Cicada (£16.95). To order a copy for £14.41 go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99