Mrs Carey’s Concert, a new documentary by Bob Connolly (of Rats in the Ranks and Facing the Music) and Sophie Raymond, offers a familiar narrative archetype: it’ll be all right on the night. It is a type of triumph over adversity set on the concert stage, which informs Hungarian director István Szabó’s Meeting Venus (1991), as well as the lives of most musicians, some of the time. When we come across it at the movies, we know it can only end well but this in no way detracts from this lovely film.

The concert in question is Methodist Ladies’ College’s biennial performance at the Sydney Opera House, which involves the entire school community. After her own conversion to music by Bach’s St Matthew Passion, music director Mrs Carey became a proselytiser for music: “I think music’s a fundamental part of what education should be. It’s intellectual … it’s an emotional pursuit, it’s a physical pursuit, it nourishes your soul. It’s also teaching them courage, it’s teaching them how to communicate.” The film tracks the progress of Emily Sun, a gifted violinist, as she moves from alleged graffitist to radiant performer. Other members of the school community are less grateful for the opportunity. Generally, they humour their teachers with an adolescent’s noblesse oblige. “Make me blush with the passion!” calls out a conductor to a room of raised eyebrows.

But 16-year-old Iris Shi is a conscientious objector, and the story’s chief villain. At first I felt a little sorry for her but it is a role she clearly relishes. “I can shut down my teachers that easily,” she says, and laughs like a criminal mastermind. In a scene that is both comic and heartbreaking, Mrs Carey launches into an eloquent plea for music, for the joys of teamwork, for the great value of this opportunity. Iris casts around for rebuttal and then suddenly finds it: “The thing is, like, you know— there’s a difference between having the opportunity and seizing it, than— you know, having an opportunity and forcing it upon someone else.”

I had been barracking for Mrs Carey but this stopped me in my tracks. What if free-thinking, ungrateful Iris has a point? Why should our children thank us for privileges they do not want? Mrs Carey is also shaken: “Why am I spending hour after hour on these kids if that really is the sum of it?” She revives herself with a bracing dose of the St Matthew Passion, reminding herself that “it’s only Iris.”

At the Opera House on concert night, Mrs Carey sports a coiffed Margaret Thatcher hairdo, as excited girls dart in and out of dressing rooms. They play like angels, of course; even Iris sings along, or at least lip-synchs. Mrs Carey is vindicated in every way; it is a relief that Iris is wrong, that these girls are enormously privileged. But the film’s eloquent message is that the privilege lies not in the Sydney Opera House, nor in the (beautifully shot) avenues of MLC – it lies instead in having teachers such as these.