You've heard most of the songs on this comp. But, like the fascinating documentary it soundtracks, what 20 Feet from Stardom asks you to do is listen to them from a different angle, one just outside the spotlight, where backup vocalists have spent their lives standing. These skilled artists added style, nuance and oomph to every song they touched. Can you imagine Lou Reed's "Walk on the Wild Side" without the "colored girls"? Besides backup-dependent songs like that, the album also features solo work by shoulda-been stars like Merry Clayton and Darlene Love.