You might remember country singer Donna Fargo, she had two crossover hits in the early1970's. The first was 'Happiest Girl in the Whole U.S.A'. then followed by 'Funny Face'.
Ms. Fargo was appearing at a hotel in Las Vegas in 1981 or 82 I'm not sure of the year, but anyway I had backstage passes. So there I was backstage while Donna Fargo was on stage singing. There were a lot of people backstage, most of them were working, running back and forth, and the rest were guests. I noticed one young woman just standing backstage wearing a set of headphones and holding a microphone; the same kind that Donna Fargo was using on stage.
Then it happened. When the song Donna Fargo was singing required her to hit a high note that lasted several seconds, that girl backstage sang it, with the microphone she was holding. Donna Fargo looked like she was holding the note but no sound came from her for those few seconds. It happened several times during the show.
I wish I hadn't seen that! Enjoy the video.