When 20 Feet From Stardom scooped the Best Documentary award at the Oscars earlier this year, there were a number of mutterings. Many critics felt The Act of Killing was a more deserving candidate, rather than something that could be seen to be a lightweight, slightly vapid piece of academy-soothing fluff. But it would be a shame if such a view became entrenched. Not because The Act… is not an incredibly important piece of cinema; but because you’d be hard pressed to find a less accurate description of this stunning piece of work.

There’s nothing especially ground-breaking in the way the film is shot – the real talent lies in the stories. Focusing on several prominent backing singers – Merry Clayton, Darlene Love & Lisa Fischer among others – we chart the history of popular American music from the mid-fifties onwards. The comparison is often drawn between gospel songs that praise God and secular songs that praise sex, and one thing the film has in abundance is soul. As well as a plethora of interviews and rarely seen archive footage, there’s a revelling in the sheer joy of singing, with incredibly intimate sections that feature unaccompanied vocal performances that chill the spine and wet the eyes.

There is one problem; and that is the sheer volume of anger generated. Watching women of such talent catalogue a series of attempted shots at the leading role, it sets the blood rising. Current ‘stars’ (and never has the word been so stretched) release a new record, sounding pitch perfect thanks to the miracle of auto-tune. And then they perform live on the X Factor, sounding like the third-rate karaoke singers that the judges claim to have no time for, only to be praised to the hilt for their spectacular mediocrity. Katy Perry, Pixie Lott, Girls Aloud; the allegedly great Madonna; take your pick of disappointment. This is by no means a new observation. But that’s why this film should be widely seen. A reminder that talent and record sales ought to go hand in hand.