Thanks for the link to that story. I’m amazed. I always took that to be the voice of a black girl. Gut wrenching emotion in her vocals.
The one female solo I think matches that is the part in the Rolling Stones “Gimme shelter”, I’ll link it if I can find it. I read someplace that the singer who did it (a black girl) was called up in much the same way, unexpectedly.
She was pregnant at the time apparently, and after leaving the studio she had a miscarriage.