Paddy Kehoe hails the Oscar-winning music documentary - in cinemas now.

This utterly absorbing film tells the story of the backing singers who lent immense vocal power to so many great pop singles. 

As is only right, the lead singers themselves pay generous tribute. Stevie Wonder, for instance, demonstrates the integral role which Ray Charles' backing singers, the Raelettes, had in the song What I'd Say. Stevie sings Ray's lines a cappella, then leaves a gap after each line, so you get sudden silence, instead of the women's powerful contribution. What I'd Say has its roots in the call-and-response format of Southern Baptist church services; the fathers of many of these backing singers had been pastors.

In the early Fifties, backing singers were demure and mostly white. The Sixties welcomed not just black singers, but a ready group of black backing vocalists. Any one of these back-up artists might, with luck, make it in their own right as a solo performer.

Meanwhile, Phil Spector, a gifted Svengali, built his Wall of Sound and controlled the scene, without apparent sensitivity. One of his protégés heard herself singing on the car radio, but to her chagrin, The Crystals were credited with the performance. Similarly, Ike Turner controlled not just his female backing singers, The Ikettes, but his wife Tina. They were all working for him.

As well as documenting an unsung sector of showbiz, 20 Feet from Stardom is also a salutary lesson about the madness of chasing fame, even when you have the talent. Bruce Springsteen and Sting are insightful contributors, both soberly aware of how luck and circumstances play their part. 

Mick Jagger recalls the recording of Gimme Shelter, and Merry Clayton singing the "It's just a shot away" line at 2am, one morning in 1969. Clayton had been woken at 7pm by producer Jack Nitzsche, who told her to get to the session. It was perhaps the best wake-up call she ever got.