The crazy dream of performing Havergal Brian’s gargantuan Gothic paid off. Now there’s a film about the journey.

Is it the work of a genius, prankster or megalomaniac?

Over the years Havergal Brian’s herculean Gothic Symphony has been dismissed – and championed – by some of the world’s great conductors. It’s not just the whopping numbers – an orchestral team of around 180, four brass bands, four soloists and four mixed choirs – that makes a performance such a mammoth and economically tough project.

It’s also rumoured to be fiendish to play, treacherous to sing and nigh on impossible without months of intensive rehearsal. A citation in the 1974 Guinness World Records as the biggest symphony ever has done nothing to help its artistic reputation, but has certainly contributed to the work’s cult status.

In 2010, the eyes of the world were trained on Brisbane as a dedicated crew set out to stage the first performance of this juggernaut outside of Britain, and only the fourth since it emerged back in 1932. Now, a documentary film about the seven-year process of getting the Gothic off the ground is screening in...