It's not interesting to sit through per se, but it's one of the rare examples that would have thrilled arthouse and beatnik poetry slam aficionados while most moviegoers were lining up to watch Funny Girl, Bullitt and Planet of the Apes .

It's also the kind of thing you have to respect any filmmaker did back in the late 60s, decades before this kind of thing could be done (and overdone) with far more mobile digital cameras or even phones.

Is it a movie about the creative muse? About the process of making movies? In the DVD era we all learned how much work actually went on behind the scenes to create a simple shot like a married couple having an argument on a bridge in Central Park (as the film within a film here deals with), but back then, maybe writer/director/star William Greaves wanted to peel back the curtain by having himself and his crew tell the story of the telling the story.

We start with two people sitting in the sunshine rehearsing the scene after a husband has caught up to his wife as she walks angrily through the park, demanding to know why she's sore at him and with her incredulous that he has no idea, obliquely alluding to her knowing that he's secretly gay and has been sleeping with other men behind her back.

Later on, the couple – Alice and Freddy – are played by completely different actors, Greaves and his crew trying to wrangle angles of sunlight, film cartridges, a cop wanting to see their permit and more as they try to capture the scene, the actors themselves sometimes holding the proceedings up while they try to find muses and make sense of their dialogue.

And someone else is filming Greaves as he tries to keep the whole circus on track, as if documenting it for a Behind the Scenes documentary we might see on TV – except that here, it's the film itself. In fact the entire runtime is concerned with the production only trying to capture the single scene of the marital argument. We never get a glimpse of the movie Greaves is making the argument scene is going to be situated in.

The action also breaks off from the Central Park shoot to show us the senior crewmembers (minus Greaves) sitting around in a room all talking about the merits or folly of what he's attempting.

It's very experimental, very meta-commenting-upon-meta and full of social theory about the arts and film, and not all that social theory will be terribly obvious. Maybe it was just an attempt at the appeal of reality TV before such a thing existed rather than some subtextual comment on watching the watchers, Rear Window -style.

Greaves was a documentary director and producer who worked on hundreds of films, maybe he was just slightly punch drunk by the grind of the process and wanted to put that feeling on film himself.

It was also thoroughly impossible to release to mainstream audiences so it never went anywhere – after Greaves finally finished it and flew it to the Cannes Film Festival himself they apparently screened the reels out of order, further damning its commercial chances. He also apparently planned a five-arc series, finally filming a sequel in 2005 a few years before he died.

As I said it's not the most interesting story to watch but – no doubt as Greaves intended – it shows you a cinema form that wasn't at all widely accepted back then.

Luckily for him, it was given a new lease on life, Ed Wood-style, by various celebrity fans (Steve Buscemi and Steven Soderbergh, in this case) and rode the wave all the way to cult status and the Criterion Collection treatment.