Martha and the Vandellas
In a scene from Nothing But A Man, that played in Berkeley just off Telegraph Avenue in 1964, Abbey Lincoln goes to the jukebox in a roadside tavern, puts a coin in and out comes Heatwave by Martha and the Vandellas.
Nothing But A Man is a superb film and Martha Reeves' vocal is on the edge of the music. It's dangerous—this is the only way I can describe it—she could go too far and fall, or not far enough and fail. But she's there and she makes it seem so easy. Rarely does one hear singing like hers.