With her librarian haircut, glasses, and knee-length dresses, Daphne Oram doesn’t look like she was on the cutting edge of anything, let alone electronic music. But looks can be deceiving. Born in 1925, she began working at the BBC in the late 1940s, as gender roles were loosening. She would later become the first woman to set up an independent music studio, and she also cofounded the BBC’s Radiophonic Workshop. Yet women like Oram were written out of electronic music and its history, which is today viewed as the ultimate boys’ club. In the new film Sisters with Transistors, Lisa Rovner shines a long overdue spotlight on the pioneering women who did more than “push around dead white men’s notes.” The archival footage is mesmerizing. —E.C.