Organisers of the 20,000-capacity independent festival Secret Garden Party (SGP) are to screen a feature-length documentary on the Cambridgeshire event when it returns this year after a five-year hiatus for its 20th-anniversary edition.

The documentary, That Was a Serious Party, directed by Dylan Harvey, will explore the festival’s appeal and how it was founded by Freddie Fellowes as a 700-capacity event. It will feature clips of archive footage, user-created content, filmed interviews and cartoons by comic book artist Pete Loveday.

The film by Bohemia Media will be screened during the event’s opening day on 21 July and will also be available on digital platforms such as iTunes, Amazon and Sky Store from 25 July.

Fellowes said, “In its 15-year pioneering history SGP had never allowed any backstage access to photographers let alone film makers – but in 2017 – the year we thought was our last – this changed due to the silver tongues of the director and producer of this film, Dylan and Haseeb.

“In a festival world dominated by stories of Fyre, theft and rampant commercialism; ours is a very different take on a counterculture that has taken the world by storm.”

Harvey said, “This groundbreaking event pushed the envelope when it came to pulling down the fence between artist and audience, creating an immersive world of secret and not-so-secret happenings going off across the site.

“So when in 2017 Freddie Fellowes announced that it was ending after 15 years, still at the height of its popularity, it presented us with an opportunity to bring the party vibe from field to screen by telling not just the story of this unique festival but to also use the festival as a means of exploring a culture which in those 15 years saw the transition from underground to mainstream, thanks perhaps in no small part to the rise of social media’s double-edged sword making events such as these into ‘bucket list’ moments.”