Try to imagine the Rolling Stones' "Gimme Shelter" without those dramatic backing vocals.

Or Steve Winwood's "Higher Love," David Bowie's "Young Americans," Lynyrd Skynyrd's "Sweet Home Alabama," Roxy Music's "Avalon," Lou Reed's "Walk on the Wild Side" and Aretha Franklin's "Respect."

Impossible, you say?

The fact is that backing vocals are every bit as important as guitar, bass and drums in popular music history. Yet, sadly, most fans can't name the backing vocalists who help make their favorite tunes great.

Mick Jagger, Sting, Bruce Springsteen and other big name celebrities appear in "Twenty Feet From Freedom," but make no mistake the stars of this film are the backing vocalists -- in particular, Clayton, Vega, Darlene Love, Lisa Fischer, Judith Hill and Claudia Lennear.

The film offered the rare chance for these women to step into the spotlight and finally tell their stories.

"Twenty Feet From Stardom" opened in theaters nationwide on June 14, 2013. Check your local theater for listings.