Film makers, critics and theorists have along argued over the ins and outs of auteur theory, the pros and cons of voiceovers, what's in the Pulp Fiction briefcase and the real meaning of Rosebud in Citizen Kane.

Far less energy has gone into the question of what we might mean by "folk cinema". But while it may still be little discussed in Hollywood or Cannes, a new mini-festival launching in Edinburgh this week is at least trying to start the conversation.

Folk Film Gathering 2015 bills itself as the world's first festival of folk cinema and it's running at the capital's Filmhouse as a collaboration with TradFest, now in its third year and dedicated to showcasing Scotland's traditional arts and culture. The man behind the Gathering is film-maker Jamie Chambers of arts collective Transgressive North.

"It's tricky," he laughs when asked to define folk cinema. "The word folk itself has lots of different meanings. It can mean traditional, indigenous, a place-rooted culture. There's another resonance with more urban, working class culture. That could also be considered folk. So a lot of the films bring out a different meaning of the term."

Chambers also mentions "sweded" films, which is where amateurs pick up a camera - or even a cameraphone - and either re-create well-known movies or remix them to their own eccentric ends. Predictably, Star Wars is a favourite. "The concept behind the 'sweded' film is almost like doing a cover version," he explains. "Some people are calling that folk cinema".

There are no sweded films here, though. Nor Swedish ones, either. Instead The Folk Film Gathering concentrates on works which revel in the richness of folk culture - often a dark and surreal combination of music, storytelling, art and myth - or which explore working class communities and the bonds of place and language which tie them together. Some of the films are obscure, others are relatively well known.

In that last category are Ken Loach's landmark 1965 film Up The Junction and, from a year earlier, Shadows Of Forgotten Ancestors, by much-persecuted Georgian-Armenian director Sergei Parajanov.

Loach's film was shot in Clapham in London and originally screened as part of the BBC's Wednesday Play series, where it drew the ire of Mary Whitehouse for the crime of showing "promiscuity as normal". Parajanov's work couldn't be more different. Set in the Carpathian Mountains, it presents a semi-mythical tale about two star-crossed lovers and is shot mostly in vivid colour with occasional black and white segments. It comes with a soundtrack of traditional Ukrainian folk music and a procession of weird and wonderful folk costumes, and its director had far worse than Mary Whitehouse to contend with: Parajanov had already been jailed once by the Soviet authorities when he made the film and would be again in the early 1970s.

Also scheduled for the Gathering are rarely-seen underground gems such as 1991's Dream On, made by the Newcastle-based Amber Collective, and Scottish film Play Me Something, from 1989.

Founded in 1969 and "criminally under-appreciated", according to Chambers, the Amber Collective film-makers spend years at a time making their works and fund them by becoming economic players in the community they're portraying. In the past they've owned both a pub and a racehorse. Dream On follows a women's darts team from South Shields.

"They very much embed themselves within a particular community and then very gently and organically grow the film," says Chambers. "There's a lot of resonance with Italian Neo-Realism in that there's a lot of non-actors, it's location based, and there are stories which grow out of that place."

Play Me Something, meanwhile, is directed by Timothy Neat and features a young Tilda Swinton alongside a "cast" which includes Liz Lochhead, Hamish Henderson and Margaret Bennett as passengers stranded at Barra airport who are entertained with a story.

The other films in the festival are Kaos, shot in 1984 by Italy's Taviani Brothers; 2012 Russian film Celestial Wives Of The Meadow Mari by Alexey Fedorchenko; and, from Senegal, A Letter To My Village, made in 1976 by Safi Faye and the first film by an African woman to gain international distribution. Each film will be preceded by a short film by young Scottish film-makers. Among these is Chambers's own When The Song Dies, a documentary about Scotland's oral tradition featuring the late singer Sheila Stewart, and Copycat, made by schoolchildren in Prestonpans.

Just as tricky as defining folk cinema, it seems, is tracking down examples of the form. Chambers was only able to obtain a VHS copy of Dream On, for instance, and then had to hunt down a video player on which to watch it.

"Very few people I know still have them," he laughs. "In some ways it makes me quite angry because I think this is one of the greatest British films I've ever seen and it's just so hard to get hold off and see."

It was a similar story with Play Me Something. The only way Chambers was able to actually see it was to borrow a copy from its director. Full prints have been sourced for the festival screenings, however.

If the inaugural Folk Film Gathering is a success, Chambers plans to expand it for 2016. One idea he has is to show Alexander Dovchenko's 1930 film Earth with a specially commissioned live soundtrack. And maybe we'll finally get to see Blue Black Permanent, the only feature made by the great Orcadian poet and film-maker Margaret Tait and which Chambers had to travel to London to see on a cine-viewer at the British Film Institute.

That's for the future, though. Right now, the definition of folk cinema is "up for grabs", says Chambers. And, while it may never get within touching distance, his fledgling festival is stretching its hands out to try.

Folk Film Gathering 2015 is at the Filmhouse, Edinburgh (May 1-9) as part of TradFest (April 29-May 10)