20 Feet from Stardom (2013)

You know these voices without knowing the names. Morgan Neville's film turns the camera on the backup singers behind the biggest records in rock and soul: Darlene Love, Merry Clayton, Lisa Fischer, Claudia Lennear and Judith Hill, with Mick Jagger among the stars explaining what they owed them. Hearing Clayton tell the story of her late-night "Gimme Shelter" session with the Rolling Stones is worth the whole running time. It won the Academy Award for Best Documentary Feature. Free with ads on The Roku Channel, The CW and YouTube's free movies, and free with a library card on Kanopy and Hoopla.