A hot new film, Laurel Canyon, stars Frances McDormand as a hard-livin', hard-lovin' record producer in '70s L.A. In the real world, female record producers were virtually nonexistent in the music industry. How come? NPR's Neda Ulaby investigates in a two-part series. Today: the secret history of women rock 'n' roll producers, with music from Sheryl Crow, the Fleetwoods, the Shangri-las and Missy Elliott.