It's not every day you see a group of 30-odd Aboriginal women in colourful dress on the streets of Melbourne. But then it's not every day 30-odd Aboriginal women get to attend the world premiere of a movie in which they star.

The Song Keepers is a remarkable and enormously enjoyable documentary about a rather improbable concert tour. In 2015, the Central Australian Aboriginal Women's Choir went to Germany, to sing the hymns that had been brought to this country in the 19th century by Lutheran missionaries. And they sang them in their own languages, Pitjantjatjara and Arrarnta, to a rapturous response.

Stars of The Song Keepers, the Central Australian Women's Aboriginal Choir, outside the German Lutheran Trinity Church in Melbourne. Credit:Darrian Traynor

"It's simultaneously contradictory," says director Naina Sen of her debut feature, which turns all the easy assumptions about the relationship between Indigenous and occupying cultures on their head. "You do have all the colonial stuff, but you also have this preservation of language, and sacred music, and a culture that already has sacred songs taking on another culture's sacred songs."

This choir is a relic, the last of a once-thriving scene. Lutheran missionaries translated 53 German hymns within three years of arriving in the outback in 1877, and those hymns were sung – religiously, you might say – by a plethora of choirs right up to the 1970s. But when the men drifted into country music, the choirs first became women-only and then began to dwindle.